Neutralizing prolactin receptor antibodies and their therapeutic use

ABSTRACT

The present invention is directed to pharmaceutical compositions containing one or more neutralizing prolactin receptor antibodies and antigen binding fragments, and their use in the treatment or prevention of benign disorders and indications mediated by the prolactin receptor such as endometriosis, adenomyosis, non-hormonal female contraception, benign breast disease and mastalgia, lactation inhibition, benign prostate hyperplasia, fibroids, hyper- and normoprolactinemic hair loss, and cotreatment in combined hormone therapy to inhibit mammary epithelial cell proliferation. The composition of the invention blocks prolactin receptor-mediated signaling.

The present invention provides a pharmaceutical composition containingrecombinant antigen-binding regions and antibodies and functionalfragments containing such antigen-binding regions, that specificallybind and neutralize the prolactin receptor, nucleic acid sequencesencoding the foregoing antibodies, vectors containing the same, andtheir use in the treatment and/or prevention of benign diseases andindications which benefit from inhibition of prolactin receptor mediatedsignaling such as endometriosis, adenomyosis, non-hormonal femalecontraception, benign breast disease, mastalgia, lactation inhibition,benign prostate hyperplasia, fibroids as well as hyper- andnormoprolactinemic hair loss, and cotreatment in combined hormonetherapy to inhibit mammary epithelial cell proliferation.

There is an unmet medical need for the treatment of various benigndiseases and indications such as endometriosis, adenomyosis,non-hormonal female contraception, benign breast disease, mastalgia,lactation inhibition, benign prostate hyperplasia, fibroids, hyper- andnormoprolactinemic hair loss, and prevention of mammary epithelial cellproliferation in combined (i.e. estrogen plus progestin) hormonetherapy.

Prolactin (PRL) is a polypeptide hormone composed of 199 amino acids.PRL belongs to the growth hormone (GH), placental lactogen (PL) familyof polypeptide hormones and is synthesized in lactotroph cells of thepituitary and in several extrapituitary tissues such as lymphocytes,mammary epithelial cells, the myometrium, and the prostate. Twodifferent promoters regulate pituitary and extrapituitary PRL synthesis(BioEssays 28:1051-1055, 2006).

PRL binds to the PRL receptor (PRLR), a single transmembrane receptorbelonging to the class 1 cytokine receptor superfamily (EndocrineReviews 19:225-268, 1998). The PRLR exists in three different isoforms,the short, the long, and the intermediate form that can be distinguishedby the length of their cytoplasmic tails. Upon ligand binding, asequential process leads to PRLR activation. PRL interacts via itsbinding site 1 with one PRLR molecule and then attracts via its bindingsite 2 a second receptor molecule leading to an active dimer of PRLRs.PRLR dimerization leads to the predominant activation of the JAK/STAT(Janus Kinase/Signal transducers and activators of transcription)pathway. Upon receptor dimerization, JAKs (predominantly JAK2)associated with the receptor, transphosphorylate and activate eachother. In addition the PRLR is also phosphorylated and can bind toSH2-domain containing proteins such as STATs. Receptor bound STATs aresubsequently phosphorylated, dissociate from the receptor andtranslocate to the nucleus where they stimulate transcription of targetgenes. In addition, activation of the Ras-Raf-MAPK pathway andactivation of the cytoplasmic src kinase by PRLRs have been described(for review Endocrine Reviews 19:225-268, 1998).

PRLR-mediated signaling plays a role in a variety of processes such asmammary gland development, lactation, reproduction, mammary and prostatetumor growth, autoimmune diseases, general growth and metabolism, andimmunomodulation (Endocrine Reviews 19:225-268, 1998; Annu. Rev.Physiol. 64:47-67,2002).

Currently, complete interference with PRLR-mediated signaling is notpossible. The only way to interfere with PRLR-mediated signaling is theinhibition of pituitary PRL secretion by use of bromocriptine and otherdopamine receptor 2 agonists (Nature Clinical Practice Endocrinology andMetabolism 2(10): 571-581, 2006). These agents however, do not suppressextrapituitary PRL synthesis that can compensate successfully for theinhibition of pituitary PRL synthesis leading to almost unimpairedPRLR-mediated signaling (Endocrine Reviews 19:225-268,1998). Thereforeit is not surprising that dopamine type 2 receptor agonists were notbeneficial in patients suffering from breast cancer or autoimmunediseases such as systemic lupus or rheumatoid arthritis (Breast CancerRes. Treat. 14:289-29, 1989; Lupus 7:414-419, 1998) although prolactinhas been implicated in these diseases. Local prolactin synthesis inbreast cancer cells or lymphocytes which plays a pivotal role in mammarycarcinoma or autoimmune diseases, respectively, was not blocked bydopamine receptor agonists.

Despite the above-mentioned attempts to provide means for treatment orprevention of benign diseases and indications such as endometriosis,adenomyosis, non-hormonal female contraception, benign breast diseaseand mastalgia, lactation inhibition, benign prostate hyperplasia,fibroids, hyper- and normoprolactinemic hair loss, and cotreatment incombined hormone therapy for the prevention of mammary epithelial cellproliferation no compounds are available yet to meet that need. It istherefore an object of the present invention, to solve that problem byproviding compounds that are therapeutics for these benign diseases andindications.

Now novel antibodies have been identified that are specific to and havea high affinity for PRLR and this way neutralize the PRLR-mediatedsignaling and that can deliver a therapeutic benefit to the subject.

Blockade of PRLR activation by neutralizing PRLR antibodies leads to acomplete inhibition of PRLR-mediated signaling. In contrast, dopaminereceptor agonists can only interfere with enhanced PRLR-mediatedsignaling in response to elevated pituitary prolactin secretion, but notwith enhanced PRLR-mediated signaling due to an activating PRLR mutationor due to locally elevated prolactin production.

Therefore the problem is solved by provision of a pharmaceuticalcomposition containing antibodies, antigen-binding fragments thereof, orvariants thereof for the treatment of the afore mentioned benigndiseases and indications, that bind to PRLR with high affinity,efficiently neutralize the PRLR-mediated signaling, and that arepreferably cross-reactive to PRLR from other species such as Macaccamulatta and Macacca fascicularis, Mus musculus or Rattus norvegicus.

Some PRLR antibodies have already been described in the applicationWO2008/022295 (Novartis) and in the U.S. Pat. No. 7,422,899 (Biogen).The present invention is based on the discovery of novel antibodies thatare specific to and have a high affinity for PRLR and this wayneutralize the PRLR-mediated signaling and that can deliver atherapeutic benefit to the subject (sequences of novel antibodies are asin SEQ ID NO: 34-57). The pharmaceutical composition of the inventioncontains antibodies, which may be human or humanized or chimeric orhuman engineered, and which can be used in many contexts which are morefully described herein.

Therefore an object of the present invention is a pharmaceuticalcomposition comprising antibodies or antigen-binding fragments thereof,whereby said antibodies or antigen-binding fragments antagonizeprolactin receptor-mediated signaling.

The antibodies of the pharmaceutical composition were characterized inseveral cellular systems to determine their species specificity andtheir potency as well as efficacy in different readout paradigmsaddressing the inactivation of PRLR-mediated signaling (see Examples5-10). Proliferation assays were performed with rat Nb2-11 cells(Example 6, FIG. 6) or Ba/F cells either stably transfected with thehuman PRLR (Example 5, FIG. 5) or the murine PRLR (Example 10, FIG. 10).Whereas Novartis antibody XHA 06.983 did not show activity on the ratand murine PRLR, Novartis antibody XHA06.642 showed activity on the ratPRLR but not on the murine PRLR. XHA 06.642 inhibited humanPRLR-mediated signaling (Example 5, 7, 8). The novel antibody of thepresent invention 006-H08 showed the highest potency with regard toproliferation inhibition of Ba/F cells stably transfected with the humanPRLR (Example 5, FIG. 5). The novel antibody 005-C04 of the presentinvention was the only antibody showing crossreactivity on the murine(Example 10, 9) and human PRLR (Examples 5, 7, 8). In contrast to theNovartis antibody XHA06.642 the novel antibody 005-C04 is thereforesuitable for testing the inhibition of PRLR-mediated signaling in murinemodels. All other antibodies described in this invention are specificfor the human PRLR. In addition to cellular proliferation assays(Examples 5, 6, 10), luciferase reporter assays were performed usingHEK293 cells stably transfected with either the human (Example 8) ormurine (Example 9) PRLR and transiently transfected with a luciferasereporter gene under the control of LHRE's (lactogenic hormone responseelements). Using these systems the inability of the Novartis antibodyXHA06.642 to efficiently block murine PRLR-mediated signaling becameevident again (Example 9). In contrast, the novel antibody 005-C04blocked luciferase reporter gene activation by the murine PRLR (Example9). STAT5 phosphorylation in human T47D cells was used as additionalreadout to analyze the inhibitory activity of the antibodies on thehuman PRLR (Example 7, FIG. 7). As expected, unspecific antibodies wereinactive in all experimental paradigms analyzed.

The present invention relates to methods to inhibit growth ofPRLR-positive cells and the progression of the afore mentioned benigndiseases and indications by providing pharmaceutical compositionscontaining anti-PRLR antibodies. Provided are pharmaceuticalcompositions containing human monoclonal antibodies, antigen-bindingfragments thereof, and variants of the antibodies and fragments, thatspecifically bind to the extracellular domain (ECD) of PRLR (SEQ ID NO:70) or human polymorphic variants of SEQ ID No: 70 such as the 1146L and176V variants being described in PNAS 105 (38), 14533, 2008, and J.Clin. Endocrinol. Metab. 95 (1), 271, 2010.

Another object of the present invention is a pharmaceutical compositioncomprising antibodies or antigen-binding fragments thereof whereby theantibodies or antigen-binding fragments bind to epitopes of theextracellular domain of the prolactin receptor and human polymorphicvariants thereof, whereby the amino acid sequence of the extracellulardomain of the prolactin receptor corresponds to SEQ ID NO: 70, and thenucleic acid sequence corresponds to SEQ ID NO: 71.

The antibodies, antigen-binding fragments, and variants of theantibodies and fragments of the invention are comprised of a light chainvariable region and a heavy chain variable region. Variants of theantibodies or antigen-binding fragments contemplated in the inventionare molecules in which the binding activity of the antibody orantigen-binding antibody fragment for PRLR is maintained (for sequencessee table 5). Maturated forms of these antibodies are disclosed incorresponding applications.

Therefore an object of the present invention is a pharmaceuticalcomposition comprising an antibody or antigen-binding fragment thereof,whereby the antibody or the antigen-binding fragment competes to theantibodies 006-H08, 005-C04, 002-H06, 002-H08, 006-H07, 001-E06 forbinding to the epitopes of the extracellular domain of the prolactinreceptor and human polymorphic variants thereof or defined maturatedvariants thereof. The sequences of the antibodies and its maturatevariants are depicted in table 5.

In one embodiment, a pharmaceutical composition containing an antibodyor antigen-binding fragment thereof, is disclosed,

-   -   a. whereby the amino acid sequences of the variable heavy and        light regions are at least 60%, or more preferred 70%, or 80%,        still more preferred at least 90% and most preferred at least        95% identical to the sequences of the antibodies 006-H08,        005-C04, 002-H06, 002-H08, 006-H07, 001-E06 according to table        5, or    -   b. whereby the amino acid sequences of the CDR regions are at        least 60%, or more preferred 70%, or 80%, still more preferred        at least 90% and most preferred at least 95% identical to the        sequences of the antibodies 006-H08, 005-C04, 002-H06, 002-H08,        006-H07, 001-E06 according to table 5.

In one embodiment, a pharmaceutical composition containing an antibodyor antigen-binding fragments thereof are disclosed, whereby

-   -   a. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 1, 7 and 13 and the variable light        chain contains the CDR sequences corresponding to SEQ ID NO: 18,        24, and 29; or    -   b. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 2, 8 and 13 and the variable light        chain contains the CDR sequences corresponding to SEQ ID NO: 19,        25, and 30; or    -   c. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 3, 9 and 14 and the variable light        chain contains the CDR sequences corresponding to SEQ ID NO: 20,        24, and 31; or    -   d. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 4, 10 and 15 and the variable light        chain contains CDR sequences corresponding to SEQ ID NO: 21, 26,        and 32; or    -   e. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 5, 11 and 16 and the variable light        chain contains the CDR sequences corresponding to SEQ ID NO: 22,        27, and 30; or    -   f. the variable heavy chain contains the CDR sequences        corresponding to SEQ ID NO: 6, 12 and 17 and the variable light        chain contains the CDR sequences corresponding to SEQ ID NO: 23,        28, and 33.

In one embodiment, a pharmaceutical composition containing one or moreantibodies or antigen-binding fragments are disclosed, whereby

-   -   006-H08 comprises a variable heavy region corresponding to a        nucleic acid sequence according to SEQ ID NO: 46, an amino acid        sequence according to SEQ ID NO: 34; and a variable light region        with a nucleic acid sequence according to SEQ ID NO: 52, and an        amino acid sequence according to SEQ ID NO: 40,    -   002-H06 comprises an antibody having a variable heavy region        corresponding to a nucleic acid sequence according to SEQ ID NO:        47 an amino acid sequence according to SEQ ID NO: 35; and a        variable light region with a nucleic acid sequence according to        SEQ ID NO: 53, and an amino acid sequence according to SEQ ID        NO: 41,    -   002-H08 comprises an antibody having a variable heavy region        corresponding to a nucleic acid sequence according to SEQ ID NO:        48, an amino acid sequence according to SEQ ID NO: 36; and a        variable light region with a nucleic acid sequence according to        SEQ ID NO: 54, and an amino acid sequence according to SEQ ID        NO: 42,    -   006-H07 comprises an antibody having a variable heavy region        corresponding to a nucleic acid sequence according to SEQ ID NO:        49, an amino acid sequence according to SEQ ID NO: 37; and a        variable light region with a nucleic acid sequence according to        SEQ ID NO: 55, and an amino acid sequence according to SEQ ID        NO: 43,    -   001-E06 comprises an antibody having a variable heavy region        corresponding to a nucleic acid sequence according to SEQ ID NO:        50, an amino acid sequence according to SEQ ID NO: 38; and a        variable light region with a nucleic acid sequence according to        SEQ ID NO: 56, and an amino acid sequence according to SEQ ID        NO: 44, and    -   005-C04 comprises an antibody having a variable heavy region        corresponding to a nucleic acid sequence according to SEQ ID NO:        51, an amino acid sequence according to SEQ ID NO: 39; and a        variable light region with a nucleic acid sequence according to        SEQ ID NO: 57, and an amino acid sequence according to SEQ ID        NO: 45.

Table 1 provides a summary of dissociation constants and dissociationrates of representative antibodies of the pharmaceutical composition ofthe invention, as determined by surface plasmon resonance (Biacore) withmonomeric extracellular domains of PRLR (SEQ ID NO: 70) on directlyimmobilized antibodies.

TABLE 1 Monovalent dissociation constants and dissociation rates of theextracellular domain of human PRLR expressed in HEK293 cells determinedfor anti-PRLR human IgG1 molecules by surface plasmon resonance AntibodyK_(D) [M] kd [1/s] 006-H08 0.7 × 10⁻⁹ 2.4 × 10⁻⁴ 002-H06 2.7 × 10⁻⁹ 5.4× 10⁻⁴ 002-H08 1.8 × 10⁻⁹ 2.0 × 10⁻⁴ 006-H07 2.0 × 10⁻⁹ 1.3 × 10⁻³001-E06 15.8 × 10⁻⁹  4.8 × 10⁻³ 005-C04 12.2 × 10⁻⁹  9.3 × 10⁻³ HE06.6420.3 × 10⁻⁹ 3.2 × 10⁻⁴ XHA06.642 1.2 × 10⁻⁹ 1.3 × 10⁻⁴ XHA06.983 0.2 ×10⁻⁹ 1.7 × 10⁻⁴

The IgG1 format was used for the cell-based affinity determination,determined by fluorescence-activated cell sorting (FACS) combined withScatchard analysis.

Table 2 denotes the binding strength of representative IgG antibodies onthe human breast cancer cell line T47D and rat lymphoma cell line Nb2.

TABLE 2 Cell-based binding potency of anti-PRLR antibodies as determinedby FACS on the human breast cancer cell line T47D and rat lymphoma cellline Nb2 EC₅₀ [M] Antibody T47D Nb2 006-H08 1.3 × 10⁻⁹ No binding006-H07 0.4 × 10⁻⁹ No binding 001-E06 1.8 × 10⁻⁹ 1.2 × 10⁻³ 005-C04 1.9× 10⁻⁹ 0.5 × 10⁻⁹ HE06.642 1.8 × 10⁻⁹ 0.9 × 10⁻⁹ XHA06.642 1.5 × 10⁻⁹1.1 × 10⁻⁹ XHA06.983 0.3 × 10⁻⁹ No binding

Antibody Generation

To isolate a panel of antibodies able to functionally block the humanand murine PRLR, two formats of the synthetic human antibody phagedisplay library called n-CoDeR® from Bioinvent (Soderlind et al. 2000,Nature BioTechnology. 18, 852-856.), expressing scFv and Fab fragments,respectively, were investigated in parallel. The targets used for scFvor Fab selection were the soluble ECD of human PRLR (amino acidpositions 1 to 210 of SEQ ID NO. 70) and mouse PRLR (amino acidpositions 1 to 210 of SEQ ID NO: 72), applied as biotinylated (NHS-LCbiotin, Pierce) and as non-biotinylated variant as well as the humanbreast cancer cell line T47D expressing PRLR.

A combination of various approaches in phage-display technology (PDT)was used to isolate high affinity, PRLR-specific, human monoclonalantibodies, by a combination of protein and whole cell pannings andthrough the development of specific tools. The panning tools andscreening methods include the ECD of the human and mouse PRLRrecombinantly expressed in fusion with an Fc domain (R&D Systems,catalogue no. 1167-PR and 1309-PR, respectively; pos. 1-216 of SEQ IDNO: 70 and 72, respectively, each fused to the human IgG1 Fc domain,pos. 100 to 330 of human IgG1), the extracellular domain of the humanPRLR recombinantly expressed in fusion with a six-histidine tag (SEQ IDNO: 70), the HEK293 and the murine lymphoma cell line Ba/F each stablytransfected with human and murine PRLR, respectively, and the breastcancer cell line T47D and the rat lymphoma cell Nb2 each naturallyexpressing PRLR as well as the development of panning procedures andscreening assays capable of identifying neutralizing antibodies thatpreferentially bind to PRLR displayed on the cell surface and that arecross-reactive to PRLR from mouse and rat (see example 6 and 10).

Screening was performed by first identifying binders for human PRLR andeventually mouse PRLR in ELISA tests using recombinantly expressedantigens. Then, cell binding of the Fab and scFv fragments on T47D cellswas examined by FACS analyses followed by testing the neutralizingactivity of these agents on intracellular signaling. For this purpose,inhibition of phosphorylation of PRLR, of STAT5 and of ERK1/2 in T47Dcells was determined (see example 14). The best function blocking scFvsand Fabs were converted into full IgG1 molecules and tested formonovalent affinities to the ECD of PRLR and for inhibitory activity inluciferase reporter gene assays as well as in proliferation assays withcells growing in dependence of prolactin. The combination of thesespecific methods allowed the isolation of the novel antibodies‘006-H08’, ‘002-H06’, ‘002-H08’, ‘006-H07’, ‘001-E06’, ‘005-C04’ of thepresent invention.

Peptide Variants

Antibodies of the invention are not limited to the specific peptidesequences provided herein. Rather, the invention also embodies variantsof these polypeptides. With reference to the instant disclosure andconventionally available technologies and references, the skilled workerwill be able to prepare, test and utilize functional variants of theantibodies disclosed herein, while appreciating that variants having theability to bind and to functionally block PRLR fall within the scope ofthe present invention.

A variant can include, for example, an antibody that has at least onealtered complementarity determining region (CDR) (hyper-variable) and/orframework (FR) (variable) domain/position, vis-à-vis a peptide sequencedisclosed herein. To better illustrate this concept, a brief descriptionof antibody structure follows.

An antibody is composed of two peptide chains, each containing one(light chain) or three (heavy chain) constant domains and a variableregion (VL, VH), the latter of which is in each case made up of four FRregions (VH: HFR1, HFR2, HFR3, HFR4; VL: LFR1, LFR2, LFR3, LFR4) andthree interspaced CDRs (VL: LCDR1, LCDR2, LCDR3; VH: HCDR1, HCDR2,HCDR3). The antigen-binding site is formed by one or more CDRs, yet theFR regions provide the structural framework for the CDRs and, hence,play an important role in antigen binding. By altering one or more aminoacid residues in a CDR or FR region, the skilled worker routinely cangenerate mutated or diversified antibody sequences, which can bescreened against the antigen, for new or improved properties, forexample.

FIG. 12 provides the schemes for numbering each amino acid position inthe variable domains VL and VH. Tables 3 (VH) and 4 (VL) delineate theCDR regions for certain antibodies of the invention and compare aminoacids at a given position to each other and to a corresponding consensusor “master gene” sequence, in which the CDR regions are marked with ‘X’.Table 5 and 6 help to assign the SEQ ID Numbers to the antibodies,antibody fragments and PRLR variants provided in this invention.

TABLE 3 VH Sequences

TABLE 4 VL Sequences

TABLE 5 Sequences of the antibodies Antibody VH VL VH VL HCDR1 HCDR2HCDR3 LCDR1 LCDR2 LCDR3 Protein Protein Nucleotide Nucleotide SEQ ID SEQID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID 006-H08 1 713 18 24 29 34 40 46 52 002-H06 2 8 13 19 25 30 35 41 47 53 002-H08 3 914 20 24 31 36 42 48 54 006-H07 4 10 15 21 26 32 37 43 49 55 001-E06 511 16 22 27 30 38 44 50 56 005-C04 6 12 17 23 28 33 39 45 51 57 HE06.642— — — — — — 58 61 64 67 XHA06.642 — — — — — — 59 62 65 68 XHA06.983 — —— — — — 60 63 66 69

TABLE 6 Sequences of PRLR variants Antibody SEQ ID Human ECD PRLR(Protein) 70 Human ECD PRLR (Nucleotide) 71 Murine ECD PRLR (Protein) 72Murine ECD PRLR (Nucleotide) 73

The skilled worker can use the data in Tables 3, 4 and 5 to designpeptide variants that are within the scope of the present invention. Itis preferred that variants are constructed by changing amino acidswithin one or more CDR regions; a variant might also have one or morealtered framework regions (FR). For example, a peptide FR domain mightbe altered where there is a deviation in a residue compared to agermline sequence. With reference to a comparison of the novelantibodies to the corresponding consensus or “master gene” sequence,which are listed in FIG. 12, candidate residues that can be changedinclude e.g. the following ones:

-   -   residue lysine (K) at position 75 to glutamine (Q) in VH 006-H08        (SEQ ID 34)    -   residue leucine (L) at position 108 to methionine (M) in VH        006-H08 (SEQ ID 34)    -   residue threonine (T) at position 110 to isoleucine (I) in VH        006-H08 (SEQ ID 34)    -   residue phenylalanine (F) at position 67 to leucine (L) in VH        002-H08 (SEQ ID 36).        Furthermore, variants may be obtained by maturation, i. e. by        using one antibody as starting point for optimization by        diversifying one or more amino acid residues in the antibody,        preferably amino acid residues in one or more CDRs, and by        screening the resulting collection of antibody variants for        variants with improved properties. Particularly preferred is        diversification of one or more amino acid residues in LCDR3 of        VL, HCDR3 of VH, LCDR1 of VL and/or HCDR2 of VH. Diversification        can be done by synthesizing a collection of DNA molecules using        trinucleotide mutagenesis (TRIM) technology [Virnekäs, B., Ge,        L., Plückthun, A., Schneider, K. C., Wellnhofer, G., and        Moroney S. E. (1994) Trinucleotide phosphoramidites: ideal        reagents for the synthesis of mixed oligonucleotides for random        mutagenesis. Nucl. Acids Res. 22, 5600].

Conservative Amino Acid Variants

Polypeptide variants may be made that conserve the overall molecularstructure of an antibody peptide sequence described herein. Given theproperties of the individual amino acids, some rational substitutionswill be recognized by the skilled worker. Amino acid substitutions,i.e., “conservative substitutions,” may be made, for instance, on thebasis of similarity in polarity, charge, solubility, hydrophobicity,hydrophilicity, and/or the amphipathic nature of the residues involved.

For example, (a) nonpolar (hydrophobic) amino acids include alanine,leucine, isoleucine, valine, proline, phenylalanine, tryptophan, andmethionine; (b) polar neutral amino acids include glycine, serine,threonine, cysteine, tyrosine, asparagine, and glutamine; (c) positivelycharged (basic) amino acids include arginine, lysine, and histidine; and(d) negatively charged (acidic) amino acids include aspartic acid andglutamic acid. Substitutions typically may be made within groups(a)-(d). In addition, glycine and proline may be substituted for oneanother based on their ability to disrupt a-helices. Similarly, certainamino acids, such as alanine, cysteine, leucine, methionine, glutamicacid, glutamine, histidine and lysine are more commonly found inα-helices, while valine, isoleucine, phenylalanine, tyrosine, tryptophanand threonine are more commonly found in β-pleated sheets. Glycine,serine, aspartic acid, asparagine, and proline are commonly found inturns. Some preferred substitutions may be made among the followinggroups: (i) S and T; (ii) P and G; and (iii) A, V, L and I. Given theknown genetic code, and recombinant and synthetic DNA techniques, theskilled scientist readily can construct DNAs encoding the conservativeamino acid variants.

As used herein, “sequence identity” between two polypeptide sequences,indicates the percentage of amino acids that are identical between thesequences. “Sequence homology” indicates the percentage of amino acidsthat either are identical or that represent conservative amino acidsubstitutions. Preferred polypeptide sequences of the invention have asequence identity in the CDR regions of at least 60%, more preferably,at least 70% or 80%, still more preferably at least 90% and mostpreferably at least 95%. Preferred antibodies also have a sequenceidentity in the CDR regions of at least 80%, more preferably 90% andmost preferably 95%. The preferred polypeptides block prolactin receptormediated signaling.

DNA Molecules of the Invention

The present invention also relates to the DNA molecules that encode anantibody of the invention. These sequences include, but are not limitedto, those DNA molecules set forth in SEQ ID NOs 46-57.

DNA molecules of the invention are not limited to the sequencesdisclosed herein, but also include variants thereof. DNA variants withinthe invention may be described by reference to their physical propertiesin hybridization. The skilled worker will recognize that DNA can be usedto identify its complement and, since DNA is double stranded, itsequivalent or homolog, using nucleic acid hybridization techniques. Italso will be recognized that hybridization can occur with less than 100%complementarity. However, given appropriate choice of conditions,hybridization techniques can be used to differentiate among DNAsequences based on their structural relatedness to a particular probe.For guidance regarding such conditions see, Sambrook et al., 1989[Sambrook, J., Fritsch, E. F. and Maniatis, T. (1989) Molecular Cloning:A laboratory manual, Cold Spring Harbor Laboratory Press, Cold SpringHarbor, USA)] and Ausubel et al., 1995 [Ausubel, F. M., Brent, R.,Kingston, R. E., Moore, D. D., Sedman, J. G., Smith, J. A., & Struhl, K.eds. (1995). Current Protocols in Molecular Biology. New York: JohnWiley and Sons].

Structural similarity between two polynucleotide sequences can beexpressed as a function of “stringency” of the conditions under whichthe two sequences will hybridize with one another. As used herein, theterm “stringency” refers to the extent that the conditions disfavorhybridization. Stringent conditions strongly disfavor hybridization, andonly the most structurally related molecules will hybridize to oneanother under such conditions. Conversely, non-stringent conditionsfavor hybridization of molecules displaying a lesser degree ofstructural relatedness. Hybridization stringency, therefore, directlycorrelates with the structural relationships of two nucleic acidsequences. The following relationships are useful in correlatinghybridization and relatedness (where T_(m) is the melting temperature ofa nucleic acid duplex):

T _(m)=69.3+0.41(G+C)%   a.

-   -   b. The T_(m) of a duplex DNA decreases by 1° C. with every        increase of 1% in the number of mismatched base pairs.

T _(m))_(μ2)−(T _(m))_(μ1)=18.5 log₁₀μ2/μ1   c.

-   -   where μ1 and μ2 are the ionic strengths of two solutions.

Hybridization stringency is a function of many factors, includingoverall DNA concentration, ionic strength, temperature, probe size andthe presence of agents which disrupt hydrogen bonding. Factors promotinghybridization include high DNA concentrations, high ionic strengths, lowtemperatures, longer probe size and the absence of agents that disrupthydrogen bonding. Hybridization typically is performed in two phases:the “binding” phase and the “washing” phase.

First, in the binding phase, the probe is bound to the target underconditions favoring hybridization. Stringency is usually controlled atthis stage by altering the temperature. For high stringency, thetemperature is usually between 65° C. and 70° C., unless short (<20 nt)oligonucleotide probes are used. A representative hybridization solutioncomprises 6×SSC, 0.5% SDS, 5× Denhardt's solution and 100 μg ofnonspecific carrier DNA [see Ausubel et al., section 2.9, supplement 27(1994)]. Of course, many different, yet functionally equivalent, bufferconditions are known. Where the degree of relatedness is lower, a lowertemperature may be chosen. Low stringency binding temperatures arebetween about 25° C. and 40° C. Medium stringency is between at leastabout 40° C. to less than about 65° C. High stringency is at least about65° C.

Second, the excess probe is removed by washing. It is at this phase thatmore stringent conditions usually are applied. Hence, it is this“washing” stage that is most important in determining relatedness viahybridization. Washing solutions typically contain lower saltconcentrations. One exemplary medium stringency solution contains 2×SSCand 0.1% SDS. A high stringency wash solution contains the equivalent(in ionic strength) of less than about 0.2×SSC, with a preferredstringent solution containing about 0.1×SSC. The temperatures associatedwith various stringencies are the same as discussed above for “binding.”The washing solution also typically is replaced a number of times duringwashing. For example, typical high stringency washing conditionscomprise washing twice for 30 minutes at 55° C. and three times for 15minutes at 60° C.

Accordingly, subject of the present invention is an isolated nucleicacid sequence that encodes the antibody and antigen-binding fragmentsfor the composition of the present invention.

Another embodiment of the present invention is the afore mentionedisolated nucleic acid sequence, which encodes the antibodies for thecomposition of the present invention, whereby the nucleic acid sequencesare as given in table 5.

Accordingly, the present invention includes nucleic acid molecules thathybridize to the molecules of set forth in table 5 under high stringencybinding and washing conditions, where such nucleic molecules encode anantibody or functional fragment thereof having properties as describedherein. Preferred molecules (from an mRNA perspective) are those thathave at least 75% or 80% (preferably at least 85%, more preferably atleast 90% and most preferably at least 95%) homology or sequenceidentity with one of the DNA molecules described herein.

Functionally Equivalent Variants

Yet another class of DNA variants within the scope of the invention maybe described with reference to the product they encode. Thesefunctionally equivalent genes are characterized by the fact that theyencode the same peptide sequences found in SEQ ID No: 34-45 due to thedegeneracy of the genetic code.

It is recognized that variants of DNA molecules provided herein can beconstructed in several different ways. For example, they may beconstructed as completely synthetic DNAs. Methods of efficientlysynthesizing oligonucleotides in the range of 20 to about 150nucleotides are widely available. See Ausubel et al., section 2.11,Supplement 21 (1993). Overlapping oligonucleotides may be synthesizedand assembled in a fashion first reported by Khorana et al., J. Mol.Biol. 72:209-217 (1971); see also Ausubel et al., supra, Section 8.2.Synthetic DNAs preferably are designed with convenient restriction sitesengineered at the 5′ and 3′ ends of the gene to facilitate cloning intoan appropriate vector.

As indicated, a method of generating variants is to start with one ofthe DNAs disclosed herein and then to conduct site-directed mutagenesis.See Ausubel et al., supra, chapter 8, Supplement 37 (1997). In a typicalmethod, a target DNA is cloned into a single-stranded DNA bacteriophagevehicle. Single-stranded DNA is isolated and hybridized with anoligonucleotide containing the desired nucleotide alteration(s). Thecomplementary strand is synthesized and the double stranded phage isintroduced into a host. Some of the resulting progeny will contain thedesired mutant, which can be confirmed using DNA sequencing. Inaddition, various methods are available that increase the probabilitythat the progeny phage will be the desired mutant. These methods arewell known to those in the field and kits are commercially available forgenerating such mutants.

Recombinant DNA Constructs and Expression

The present invention further provides recombinant DNA constructscomprising one or more of the nucleotide sequences of the presentinvention. The recombinant constructs of the present invention are usedin connection with a vector, such as a plasmid, phagemid, phage or viralvector, into which a DNA molecule encoding an antibody of the inventionis inserted.

The encoded gene may be produced by techniques described in Sambrook etal., 1989, and Ausubel et al., 1989. Alternatively, the DNA sequencesmay be chemically synthesized using, for example, synthesizers. See, forexample, the techniques described in OLIGONUCLEOTIDE SYNTHESIS (1984,Gait, ed., IRL Press, Oxford), which is incorporated by reference hereinin its entirety. The expert in the field is able to fuse DNA encodingthe variable domains with gene fragments encoding constant regions ofvarious human IgG isotypes or derivatives thereof, either mutated ornon-mutated. He is able to apply recombinant DNA technology in order tofuse both variable domains in a single chain format using linkers suchas a fifteen-amino acid stretch containing three timesglycine-glycine-glycine-glycine-serine. Recombinant constructs of theinvention are comprised with expression vectors that are capable ofexpressing the RNA and/or protein products of the encoded DNA(s). Thevector may further comprise regulatory sequences, including a promoteroperably linked to the open reading frame (ORF). The vector may furthercomprise a selectable marker sequence. Specific initiation and bacterialsecretory signals also may be required for efficient translation ofinserted target gene coding sequences.

The present invention further provides host cells containing at leastone of the DNAs of the present invention. The host cell can be virtuallyany cell for which expression vectors are available. It may be, forexample, a higher eukaryotic host cell, such as a mammalian cell, alower eukaryotic host cell, such as a yeast cell, and may be aprokaryotic cell, such as a bacterial cell. Introduction of therecombinant construct into the host cell can be effected by calciumphosphate transfection, DEAE, dextran mediated transfection,electroporation or phage infection.

Bacterial Expression

Useful expression vectors for bacterial use are constructed by insertinga structural DNA sequence encoding a desired protein together withsuitable translation initiation and termination signals in operablereading phase with a functional promoter. The vector will comprise oneor more phenotypic selectable markers and an origin of replication toensure maintenance of the vector and, if desirable, to provideamplification within the host. Suitable prokaryotic hosts fortransformation include E. coli, Bacillus subtilis, Salmonellatyphimurium and various species within the genera Pseudomonas,Streptomyces, and Staphylococcus.

Bacterial vectors may be, for example, bacteriophage-, plasmid- orphagemid-based. These vectors can contain a selectable marker andbacterial origin of replication derived from commercially availableplasmids typically containing elements of the well known cloning vectorpBR322 (ATCC 37017). Following transformation of a suitable host strainand growth of the host strain to an appropriate cell density, theselected promoter is de-repressed/induced by appropriate means (e.g.,temperature shift or chemical induction) and cells are cultured for anadditional period. Cells are typically harvested by centrifugation,disrupted by physical or chemical means, and the resulting crude extractretained for further purification.

In bacterial systems, a number of expression vectors may beadvantageously selected depending upon the use intended for the proteinbeing expressed. For example, when a large quantity of such a protein isto be produced, for the generation of antibodies or to screen peptidelibraries, for example, vectors which direct the expression of highlevels of fusion protein products that are readily purified may bedesirable.

Mammalian Expression & Purification

Preferred regulatory sequences for mammalian host cell expressioninclude viral elements that direct high levels of protein expression inmammalian cells, such as promoters and/or enhancers derived fromcytomegalovirus (CMV) (such as the CMV promoter/enhancer), Simian Virus40 (SV40) (such as the SV40 promoter/enhancer), adenovirus, (e.g., theadenovirus major late promoter (AdMLP)) and polyoma. For furtherdescription of viral regulatory elements, and sequences thereof, seee.g., U.S. Pat. No. 5,168,062 by Stinski, U.S. Pat. No. 4,510,245 byBell et al. and U.S. Pat. No. 4,968,615 by Schaffner et al. Therecombinant expression vectors can also include origins of replicationand selectable markers (see e.g., U.S. Pat. Nos. 4,399,216, 4,634,665and U.S. Pat. No.5,179,017, by Axel et al.). Suitable selectable markersinclude genes that confer resistance to drugs such as G418, hygromycinor methotrexate, on a host cell into which the vector has beenintroduced. For example, the dihydrofolate reductase (DHFR) gene confersresistance to methotrexate and the neo gene confers resistance to G418.

Transfection of the expression vector into a host cell can be carriedout using standard techniques such as electroporation, calcium-phosphateprecipitation, and DEAE-dextran transfection.

Suitable mammalian host cells for expressing the antibodies, antigenbinding portions, or derivatives thereof provided herein include ChineseHamster Ovary (CHO cells) [including dhfr-CHO cells, described in Urlauband Chasin, (1980) Proc. Natl. Acad. Sci. USA 77:4216-4220, used with aDHFR selectable marker, e.g., as described in R. J. Kaufman and P. A.Sharp (1982) Mol. Biol. 159:601-621]], NSO myeloma cells, COS cells andSP2 cells. In some embodiments, the expression vector is designed suchthat the expressed protein is secreted into the culture medium in whichthe host cells are grown. The antibodies, antigen binding portions, orderivatives thereof can be recovered from the culture medium usingstandard protein purification methods.

Antibodies of the invention or an antigen-binding fragment thereof canbe recovered and purified from recombinant cell cultures by well-knownmethods including, but not limited to ammonium sulfate or ethanolprecipitation, acid extraction, Protein A chromatography, Protein Gchromatography, anion or cation exchange chromatography,phospho-cellulose chromatography, hydrophobic interactionchromatography, affinity chromatography, hydroxylapatite chromatographyand lectin chromatography. High performance liquid chromatography(“HPLC”) can also be employed for purification. See, e.g., Colligan,Current Protocols in Immunology, or Current Protocols in ProteinScience, John Wiley & Sons, NY, N.Y., (1997-2001), e.g., Chapters 1, 4,6, 8, 9, 10, each entirely incorporated herein by reference.

Antibodies of the present invention or antigen-binding fragment thereofinclude naturally purified products, products of chemical syntheticprocedures, and products produced by recombinant techniques from aeukaryotic host, including, for example, yeast, higher plant, insect andmammalian cells. Depending upon the host employed in a recombinantproduction procedure, the antibody of the present invention can beglycosylated or can be non-glycosylated. Such methods are described inmany standard laboratory manuals, such as Sambrook, supra, Sections17.37-17.42; Ausubel, supra, Chapters 10, 12, 13, 16, 18 and 20.

Endometriosis and Adenomyosis (Endometriosis Interna)

Endometriosis is a benign, estrogen-dependent, gynecological disorderthat is characterized by the presence of endometrial tissue (glands andstroma) outside the uterine cavity. Endometriotic lesions are mainlyfound on the pelvic peritoneum, in the ovaries and the rectovaginalseptum (Obstet. Gynecol. Clin. North. Am. 24:235-238, 1997).Endometriosis is often associated with infertility and pain symptomssuch as dysmenorrhoea. In addition, many patients suffer from autoimmunediseases (Hum. Reprod. 17(19):2715-2724, 2002). Adenomyosis uteri alsoknown as endometriosis interna describes a subform of endometriosiswhich is restricted to the uterus. In case of adenomyosis uteri,endometrial glands invade the myometrium and the uterine wall.

According to the transplantation theory, endometrial fragments areflushed by retrograde menstruation into the peritoneal cavity in both,patients and healthy women (Obstet. Gynecol. 64:151-154, 1984). Fourmain factors seem to be critically involved in the successfulestablishment of endometriotic lesions in the pelvic cavity of patients:

-   -   a) In the late secretory phase of the menstrual cycle,        endometrial cells in healthy women become apoptotic. In        patients, the extent of apoptosis in endometrial cells is        clearly reduced (Fertil. Steril. 69:1042-1047,1998). Therefore,        in patients there is a higher probability than in healthy women,        that endometrial fragments that have been flushed into the        peritoneal cavity by retrograde menstruation do not die and        implant successfully.    -   b) For successful implantation in the peritoneum and long-term        survival of the ectopic endometrial fragments, new blood vessels        have to form (British Journal of Pharmacology, 149:133-135,        2006).    -   c) Many patients suffer from autoimmune disease and thus have a        compromised immune system (Hum. Reprod. 17(19): 2002, 2715-2724,        2002). This may lead to the conclusion that an intact immune        response—as it is present in healthy women—may play a role for        the prevention of the establishment of endometriotic lesions.    -   d) Lesions have to grow and thus depend on the presence of        mitogenic stimuli and growth factors.

For the treatment of endometriosis, the following approaches existcurrently:

-   -   a) Gonadotropin-releasing hormone (GnRH) analogues: lead to        suppression of ovarian estradiol synthesis and induce atrophy of        ectopic endometriotic implants that depend critically on the        presence of estradiol for growth.    -   b) Aromatase inhibitors: inhibit the local production of        estradiol by endometriotic implants, induce apoptosis and        inhibit proliferation of ectopic endometriotic fragments.    -   c) Selective estrogen receptor modulators: have estrogen        receptor antagonistic activity in normal endometrial and ectopic        implants and thus lead to atrophy of implanted ectopic        endometriotic tissue.    -   d) Progesterone receptor agonists: inhibit proliferation of        normal and ectopic endometrial cells, induce differentiation and        apoptosis.    -   e) Combined oral contraceptives: maintain the status quo,        prevent progression of the disease, and induce atrophy of the        ectopic and eutopic endometrium.    -   f) Surgical excision of lesions.

GnRH analogues, SERMs, and aromatase inhibitors have severe side effectsand lead to hot flushes and bone loss in young women suffering fromendometriosis. Treatment with progesterone receptor agonists leads toovulation inhibition, irregular menstrual bleeding followed byamenorrhoea, body weight gain and depression. Due to increased risk forvenous thrombembolism, combined oral contraceptives are not indicated inwomen older than 35 years, smokers and individuals suffering fromoverweight. Surgical excision of lesions is prone to high recurrencerates.

The antibodies of the pharmaceutical composition of the presentinvention interfere with PRLR-mediated signaling stimulated bypituitary- and locally-produced prolactin or due to activating PRLRmutations and are therefore more effective than dopamine-2-receptoragonists which interfere only with pituitary prolactin secretion.

PRL and the PRLR are expressed in the uterus and play a role in normaluterine physiology; PRL can act as a potent mitogen and has aimmunomodulatory role. In the present invention it is shown thatalterations in the PRL/PRLR system play a role in human endometriosis.An analysis of the expression of PRL and the PRLR in endometrium ofhealthy women and in endometrium and lesions of patients (see Example 2)by quantitative Taqman PCR is shown in FIGS. 1 and 2.

As demonstrated in FIG. 1 (PRL expression) and FIG. 2 (PRLR expression),both PRL and its receptor are strongly upregulated in endometrioticlesions. This discovery generates for the first time experimentalevidence that autocrine PRL signaling may play a fundamental role in theestablishment, growth, and maintenance of endometriotic lesions.

The PRLR antibodies were successfully tested in an animal model forendometriosis interna, i.e. adenomyosis uteri in mice (see Example 20).Adenomyosis is characterized by infiltrative growth of endometrialglands in the myometrial layer of the endometrium. It resembles anendometriosis form restricted to the uterus—the only form ofendometriosis non-menstruating species can develop. Danazol which iseffective in the clinical treatment of patients suffering fromendometriosis is also effective in the treatment of adenomyosis uteri(Life Sciences 51:1119-1125, 1992). However danazol is an androgenicprogestin and leads to severe androgenic side-effects in young women,which limits its use.

The pharmaceutical composition of the of the present invention solvesthe problem for providing new treatments or prevention for endometriosisand exhibit lesser side effects than current standard therapies.

Therefore a further aspect of the present invention is to employ apharmaceutical composition containing neutralizing PRLR antibodies andantigen binding fragments for the treatment or prevention ofendometriosis and adenomyosis (endometriosis interna), whereby suchantibodies can be the ones as disclosed in the present invention.

Non-Hormonal Female Contraception

Current approaches for female contraception are the following:

-   -   a) Combined oral contraceptives containing estrogens and        progestins. The progestogenic component mediates the        contraceptive effect via negative feedback on the        hypothalamic-pituitary-gonadal axis. The estrogenic component        guarantees a good bleeding control and potentiates the        gestagenic action via induction of the progesterone receptor in        target cells.    -   b) Intrauterine devices containing progestins only.    -   The locally released progestin renders the endometrium in an        implantation-resistant state. In addition, the cervical mucos        becomes almost impermeable for sperm cells.    -   c) Progestin only pills and implants.    -   The progestin inhibits ovulation via negative feedback on the        hypothalamic-pituitary-gonadal axis. In addition the        permeability of the cervical mucos for sperm cells is reduced.    -   d) Vaginal rings containing ethinylestradiol plus progestins

The main side-effect of combined oral contraceptives is the elevatedrisk for venous thromboembolism (VTE). Moreover, overweight or smokingwomen, as well as women suffering from autoimmune diseases such as lupusand women older than 35 years cannot use oral combined contraceptives.

Intrauterine devices and implants containing progestins only can lead todysfunctional uterine bleeding.

Progestin only pills can cause irregular bleeding patterns, spotting,amenorrhea. The risk for ectopic pregnancies increases. Weight gain andreductions in bone mass density are further side effects.

Vaginal rings can lead to vaginitis, leukorrhea or expulsion.

PRLR-deficient mice have been generated a few years ago (Genes Dev11:167-178, 1997). Interestingly, PRLR-deficient females, but not malemice, are completely sterile. PRLR^(−/−) females exhibited an arrest ofegg development immediately after fertilization, i.e. they showed anarrest of preimplantation development. Only very few oocytes reached theblastocyst stage and were unable to implant in mutant females butdeveloped to normal embryos in wildtype foster mothers aftertransplantation. The infertility phenotype of PRLR-deficient mice couldbe rescued until midterm pregnancy by progesterone supplementation.Obviously, PRLR-mediated signaling plays an important role in themaintenance and function of the corpus luteum producing progesteronethat is necessary to allow and maintain pregnancy. In additionPRLR-deficient females, but not males, exhibited a reduction in bodyweight associated with a reduction in abdominal fat mass and leptinlevels.

So far, no inactivating human PRLR mutation is known, therefore theprecise role of PRLR-mediated signaling in human fertility is stillunknown. However, there is increasing evidence that also in humans, aminimal prolactin level is required to allow for successful pregnancy.Patients suffering from primary infertility due to hyperprolactinemiccorpus luteum insufficiency were treated with bromocriptin. In somecases, prolactin levels were oversuppressed and shortened luteal phasesreappeared again (Bohnet HG et al. in Lisuride and other dopamineagonists edited by D.B. Caine et al, Raven Press, New York, 1983). Fromthese data it was concluded that hyper- and hypoprolactinemic statesinterfere negatively with female fertility. This can be explained by theinteraction of PRL with its receptor. In case of low prolactin levels,there is no sufficient receptor activation, whereas in case ofhyperprolactinemia, there is also no sufficient receptor activation,since all receptors are blocked by one prolactin molecule and cannotdimerize anymore. In other words, the dose response for prolactin isbell-shaped and optimal receptor activation is achieved only in acertain concentration range. There is evidence from a second study thatlack of endometrial prolactin expression in patients leads to earlyimplantation failure (Human Reprod. 19:1911-1916, 2004). Moreover, ithas been shown that ex vivo, prolactin can prevent apoptosis of culturedhuman granulosa cells and thus maintains early corpus luteum function asit has been demonstrated in PRLR-deficient mice (Human Reprod.18:2672-2677,2003).

To test the contraceptive efficacy of neutralizing PRLR antibodies, micewere injected with specific and unspecific PRLR antibodies and matedwith males as described in example 11. Readouts were litter number pertreatment group and litter size per animal.

The experiment presented in FIG. 11 demonstrates that the treatment withthe neutralizing antibody of the present invention completely preventedpregnancy in mice when tested at 30 mg/kg body weight.

Compared to the afore mentioned standard approaches, femalecontraception with neutralizing PRLR antibodies has several advantages:

-   -   the antibodies can be used in smoking, overweight, and older        women as well as in women suffering from lupus erythematodes        (PRLR antibodies might even be beneficial for the treatment of        lupus and the reduction of abdominal fat, i.e. PRLR-deficient        mice had less abdominal fat).    -   the PRLR antibodies do not elevate the VTE (venous        thrombembolic) risk    -   in contrast to estrogens and progestins used in combined oral        contraception, neutralization of PRLR-mediated signaling leads        to inhibition of breast epithelial proliferation and in contrast        to hormonal approaches for fertility control might even protect        users from breast cancer.

Another object of the present invention is the use of a pharmaceuticalcomposition containing PRLR-neutralizing PRLR antibodies and antigenbinding fragments for female contraception with reduced side effectscompared to standard treatments. Such antibodies can be the ones, butare not limited to the ones, as disclosed in the present invention.

Benign Breast Disease and Mastalgia

Benign breast disease encompasses a variety of symptoms, such asfibrocystic breast disease, fibroadenoma, mastalgia, and macrocysts.30-50% of premenopausal women suffer from fibrocystic breast disease(Epidemiol Rev 19:310-327, 1997). Depending on the women's age, benignbreast disease can present with distinct phenotypes (J Mammary GlandBiol Neoplasia 10:325-335, 2005): during the early reproductive phases(15-25 years) when lobular development in the normal breast takes place,benign breast disease results in fibroadenomas. Single giantfibroadenomas as well as multiple adenomas are observed. Thesefibroadenomas are composed of stromal as well as epithelial cells andarise from lobules. In the mature reproductive phase (25-40 years) thebreast is subject to cyclical changes during each menstrual cycle.Diseased women present with cyclical mastalgia and several nodules intheir breast. Later (35-55 years of age), the normal breast involuteswhereas in the diseased breast macrocysts and epithelial hyperplasiawith and without atypia can be observed. Those forms of benign breastdisease that are accompanied by enhanced epithelial cell proliferationhave a higher risk for developing mammary carcinomas. This risk can beup to 11% if cellular atypias are present in the proliferating cellfraction (Zentralbl Gynäkol 119:54-58,1997). 25% of women aged 60-80years also suffer from benign breast disease, often estrogen replacementtherapy or adiposity are the reasons for persisting benign breastdisease after menopause (Am J Obstet Gynecol 154:161-179, 1986).

The pathophysiology of fibrocystic breast disease is determined byestrogen predominance and progesterone deficiency that results inhyperproliferation of connective tissues (fibrosis) which is followed byfacultative epithelial cell proliferation. As already mentioned, therisk of breast cancer is elevated in patients exhibiting enhancedepithelial cell proliferation within the fibrocystic foci. Clinicallyfibrocystic breast disease presents with breast pain and breasttenderness. 70% of the patients with fibrocystic breast disease sufferfrom either corpus luteum insufficiency or anovulation (Am J Obstet154:161-179,1986). Corpus luteum insufficiency results in reducedprogesterone levels and estrogen predominance.

Mastalgia (breast pain) affects about 70% of women at some time in theirreproductive lifespan. Breast pain may or may not be associated withother criteria of the premenstrual syndrome. It has been demonstratedthat women suffering from mastalgia respond with an excess prolactinrelease after stimulation of the hypothalamic pituitary axis (ClinEndocrinol 23:699-704, 1985).

Standard therapies of benign breast disease and mastalgia are:

1) Bromocriptine

Bromocriptine as a dopamin agonist blocks only pituitary prolactinsynthesis, but not local synthesis of prolactin in the mammaryepithelial cells. It is therefore only effective in those forms ofmastalgia and benign breast disease that rely on elevated systemicprolactin levels. Major side effects of bromocriptine are:

Nausea, vomiting, edema, hypotension, dizziness, hair loss, headache,and halluzinations

2) Danazol

Danazol is an androgenic progestin that via its antigonadotrophicactivity counteracts the estrogen predominance observed in benign breastdisease. Major side effects are: Menstrual irregularities, depression,acne, hirsutism, voice deepening, and hot flushes as well as weightgain.

3) Tamoxifen

Tamoxifen is a selective estrogen receptor modulator with antiestrogenicactivity in the breast and estrogenic activity in the uterus. Major sideeffects are: postmenopausal symptoms such as bone loss and hot flushes,ovarial cysts, and endometrial carcinoma.

4) Progestins

Progestins inhibit benign breast disease via suppression of thepituitary gonadal axis, ovulation inhibition and estrogen depletion.Estrogen depletion leads to menopausal symptoms such as bone loss andhot flushes.

5) Low Dose Combined Oral Contraceptives

This treatment is not indicated in women older than 35 years of age,smoking as well as diabetic and overweight patients

In general, prolactin levels have been found to be increased in onethird of women with benign breast disease. Since estrogens enhancepituitary prolactin secretion, the increase in serum prolactin levelshas been thought to be a consequence of the predominance of estrogens inthis disease. It has been reported that an activating PRLR mutation isoften present in women suffering from multiple breastadenomas—resembling a subtype of fibrocystic breast disease (Paul Kelly,Breast Congress Turin, 2007 and Proc Natl Acad Sci 105: 14533-14538;2008).

Benign breast disease, mastalgia and premenstrual breast tension rely onone common pathophysiological mechanism: enhanced prolactin signaling.Elevated prolactin signaling can be the consequence of:

-   -   systemic hyperprolactinemia (due to pituitary adenoma)    -   local hyperprolactinemia (due to prolactin synthesis in        proliferating mammary gland epithelial cells). Local        hyperprolactinemia does not translate into elevated prolactin        levels in the blood.    -   constitutively active PRLR signaling in the presence of normal        prolactin levels (due to an activating PRLR mutation).

Given that certain forms of benign breast disease can give rise tobreast cancer there is a medical need for the treatment of this disease.

To demonstrate the efficacy of neutralizing PRLR antibodies in apreclinical model of benign breast disease, a mouse model based onsystemic hyperprolactinemia was employed. Adult Balb/c mice weretransplanted with pituitary isografts under the kidney capsule asdescribed in Example 16 (In: Methods in Mammary gland Biology and BreastCancer Research, 101-107, 2000). Systemic hyperprolactinemia causedenhanced epithelial cell proliferation in the mammary gland, andstimulated sidebranching and lobuloalveolar development in comparison tountreated virgin control mice. The most severe forms of humanfibrocystic breast diseases that bear an enhanced risk of cancerousdevelopment are characterized by increased epithelial cellproliferation. As described in Example 16, the neutralizing PRLRantibodies were tested in this Balb/c mouse model in comparison tounspecific antibodies with regard to their ability to:

-   -   block sidebranching and lobuloalveolar development    -   inhibit mammary epithelial cell proliferation    -   inhibit phosphorylation of STAT5, a transcription factor that is        normally activated and phosphorylated after PRLR activation.

As demonstrated in FIG. 15A-C neutralizing PRLR antibodies block all theabove mentioned readout paradigms in a dose-dependent manner.

Another object of the present invention is the use of a pharmaceuticalcomposition containing neutralizing PRLR antibodies or antigen bindingfragments as for example the ones described in the present invention fortreatment of benign breast disease and mastalgia in pre- andpostmenopausal women.

Lactation Inhibition

Prolactin is the main hormone involved in lactation after child birth.This is evidenced by the phenotype of PRLR-deficient mice. Evenheterozygous mice have severe lactational problems and are completelyunable to nurse their offspring (Frontiers in Neuroendocrinology22:140-145, 2001).

For many reasons, women have to stop breast feeding, i.e. maternalintake of drugs potentially dangerous to the infant, serious infections(mastitis, nephritis), profuse postpartum hemorrhage, and severematernal diseases such as diabetes, carcinoma, and debility or diseasesof the newborn. Currently, dopamine receptor agonists such asbromocriptine and lisuride are used to inhibit lactation after childbirth. However, these compounds can provoke severe side effects such asnausea, vomiting, edema, hypotension, dizziness, hair loss, headache,and halluzinations. In addition dopamine receptor agonists are notindicated in women suffering from cardiovascular disease andhypertension. A further disadvantage of bromocriptine is its short halflife time requiring drug intake 4-6 times daily over a period of 14days.

To test the efficacy of the neutralizing prolactin receptor antibodiesin mice, NMRI mice were mated with males. After birth, littersize wasadjusted to 8 animals, and females were treated with specific andunspecific antibodies directed against the PRLR as described in example15. As a measure for maternal lactation capacity, weight of theoffspring was monitored daily. Readouts are desribed in detail inexample 15 and results are depicted in FIG. 14A-D. Neutralizing PRLRantibodies show a dose-dependent inhibition of lactation and lead tomammary gland involution and reduced milk protein production.

Another object of the present invention is the use of a pharmaceuticalcomposition containing neutralizing PRLR antibodies and antigen bindingfragments as for example the ones described in the present invention forinhibition of lactation.

Benign Prostate Hyperplasia

Benign prostate hyperplasia (BPH) is the fourth most prevalenthealthcare condition in older men. Prostate enlargement is anage-dependent progressive condition that affects more than 50% of menaged 50 years of age. BPH is characterized by hyperplasia of prostaticstromal and epithelial cells, resulting in the formation of largediscrete nodules in the periurethral region of the prostate whichcompresses the urethral canal. Thus, impairment of urine flow is onemajor consequence of BPH.

Standard therapies for BPH encompass:

-   -   a) α1-adrenergic receptor antagonists (e.g. tamsulosin,        alfuzosin, terazosin, doxazosin) relief the BPH symptoms in the        lower urinary tract. They decrease bladder outlet obstruction by        blocking alpha-receptor-mediated stimulation of prostate smooth        muscle. Major side-effects are vasodilatory adverse events,        dizziness and ejaculation failure.    -   b) 5α-reductase inhibitors (e.g. finasteride)    -   5α-reductase inhibitors prevent the formation of        dihydrotestosterone, the active form of testosterone in the        prostate, which is responsible for the enlargement of the        prostate. Major side-effects are sexual dysfunction, such as        erectile disorders and decreased libido.    -   c) Transurethral resection of the prostate (TURP)    -   This surgical treatment is associated with high morbidity.        Side-effects are bleeding, incontinence, stricture formation,        loss of ejaculation, and bladder perforation.    -   d) Prostate stenting    -   A stent is inserted into the prostatic part of the urethra to        guarantee proper urine flow. Major side-effects are        encrustation, urinary tract infection, and migration of the        stent. Moreover, stents have to be removed before any        transurethral manipulation.

As described for the mammary gland, PRL and the PRLR act in anautocrine/paracrine way (J. Clin. Invest. 99:618 pp,1997) within theprostate.

Clinical studies indicate that hyperprolactinemia (and agromegaly) isassociated with prostatic enlargement and stromal accumulation ofinflammatory cells. Human growth hormone can bind to the human PRLR inthe presence of zinc which might explain why acromegaly can lead tobenign prostate hyperplasia. PRL serum levels are often elevated inpatients with BPH.

Transgenic animals overexpressing the PRL gene ubiquitously, developsevere stromal prostate hyperplasia, indicating PRL as an importantpathophysiological factor for the development of prostate hyperplasia(Endocrinology 138:4410 pp, 1997). Furthermore, local overexpression ofPRL in transgenic mice under the prostate specific probasin promoterresults in stromal expansion, accumulation of inflammatory cells andfocal epithelial dysplasia which are basic characteristics of human BPH(Endocrinology 144:2269 pp, 2003).

The PRLR is highly expressed in the prostate gland (Example 3, FIG. 3).Variation of PRLR protein expression was observed in rat prostate tissueafter hormonal depletion and treatment (Example 4, FIG. 4). In additionto the PRLR, the prostate cells express also prolactin.

As described in Example 17, male Balb/c mice received pituitaryisografts under the kidney capsule and developed benign prostatehyperplasia. The effect of neutralizing prolactin receptor antibodiesand unspecific antibodies on benign prostate hyperplasia was tested inthis model. Readout paradigms are described in Example 17. As depictedin FIG. 16, neutralizing PRLR antibodies inhibit benign prostate growthand are therefore suitable for the treatment of benign prostatehyperplasia.

Another object of the present invention is the use of a pharmaceuticalcomposition containing neutralizing PRLR antibodies and antigen bindingfragments as for example the ones described in the present invention fortreatment of benign prostate hyperplasia.

Hyperprolactinemic Hair Loss

Treatment of hair loss is still an unmet need. Scalp hair growth incycles: the anagen phase is characterized by active hair growth, thecatagen phase shows involution and is followed by the telogen phase(resting). The exogen phase (the release of the dead hair) coincideswith the end of the telogen phase. Hair loss can be the consequence ofdisturbed hair growth in any phase.

Telogen hair loss can have many triggers (physiological and emotionalstress, medical conditions, iron and zinc deficiency), importantlyandrogenic alopecia in its early stages shows telogen hair shedding(Cleveland clinic journal of medicine 2009;76:361-367). Anagen hair lossis often the consequence of radiation or chemotherapy.

Minoxidil and Finasteride are used for the treatment of androgenetichair loss, whereas glucocorticoids are used for alopecia areata. Ingeneral, all of these treatments have side-effects (finasteride: libidoloss and impotence in men, glucocorticoids: diabetes, weight gain,osteoporosis), and the problem of treating hair loss has not beencompletely solved.

In rodents, shaving experiments in adult animals were used to analyzethe effect of compounds on hair loss by using hair regrowth in theshaved area as readout paradigm (British Journal of dermatology2008;159:300-305). Shaving of adult animals (hair mostly in telogenphase) induces the anagen phase that is charactzerized by hair growth.

In the experiments as described in Example 17 (benign prostatehyperplasia), animals receiving pituitary isografts, were shaved. In thecourse of these experiments, it was unexpectedly discovered that animalswhich received pituitary isografts showed a severe impairment of hairregrowth in the shaved area. Treatment with neutralizing PRLR antibodiesbut not with unspecific antibodies stimulated hair growth (FIG. 17).This observation demonstrates that elevated prolactin receptor-mediatedsignaling is involved in hair loss. To analyze this in more detail,further shaving experiments in close analogy to previously describedexperiments were performed (British Journal of dermatology2008;159:300-305). These additional shaving experiments are described inExample 18. The experiments demonstrate that neutralising PRLRantibodies stimulate hair growth in hyper- and normoprolactinemic maleand female mice.

The antibodies of the composition of the present invention solve theproblem for providing new treatments for hyper- and normoprolactinemichair loss in women and men.

Therefore a further aspect of the present invention is to employ apharmaceutical composition containing neutralizing PRLR antibodies andantigen binding fragments for the treatment or prevention of hyper- andnormoprolactinemic hair loss. The antibodies of the composition can be,but are not limited to the ones disclosed in the present invention.

Combined Hormone Therapy

For the treatment of hot flushes in postmenopausal women still having auterus, combinations of estrogen (estradiol, or conjugated equineestrogens=CEE) and progestins (for example medroxyprogesterone acetate(MPA), progesterone, drospirenone, levonorgestrel) were used. Progestinshave to be added to inhibit estradiol-activated uterine epithelial cellproliferation. However, addition of progestins increases mammaryepithelial cell proliferation. Since both, normal as well as cancerousmammary epithelial cells respond with proliferation towards combinedestrogen plus progestin treatment, the relative risk of breast cancerwas found to be increased after CEE plus MPA treatment (JAMA233:321-333;2002).

Neutralizing PRLR antibodies when administered every month or everysecond month to women under combined hormone therapy will inhibitenhanced breast epithelial cell proliferation.

As described in Example 19, a previously developed mouse model for thequantitative analysis of progestin effects in the uterus and the breastwas employed (Endocrinology 149:3952-3959,2008). Mice wereovariectomized and were treated 14 days after ovariectomy for threeweeks with vehicle or 100 ng estradiol plus 100 mg/kg progesterone tomimick hormone replacement therapy. Animals were treated once weeklywith specific PRLR (10 mg/kg or 30 mg/kg) or unspecific antibodies (30mg/kg). The effects of neutralizing PRLR antibodies on proliferativeactivity in the breast under combined hormone therapy were analyzed.

The antibodies of the present invention solve the problem for treatingenhanced breast epithelial cell proliferation observed under combinedhormone therapy.

Another object of the present invention is the use of a pharmaceuticalcomposition containing neutralizing PRLR antibodies and antigen bindingfragments in combined hormone therapy (i.e. estrogen+progestin therapy)to inhibit mammary epithelial cell proliferation. The antibodies of thecomposition can be, but are not limited to, the ones disclosed in thepresent invention.

DEFINITIONS

The target antigen human “PRLR” as used herein refers to a humanpolypeptide having substantially the same amino acid sequence in itsextracellular domain as the amino acid positions 1 to 210 of SEQ ID NO.70 and naturally occurring allelic and/or splice variants thereof. “ECDof PRLR” as used herein refers to the extracellular portion of PRLRrepresented by the afore mentioned amino acids. In addition the targethuman PRLR also encompasses mutated versions of the receptor, such asthe activating mutation 1146L described by Paul Kelly (Proc Natl AcadSci USA. 105(38):14533-14538, 2008; and oral communication Turin, 2007).

As used herein, the phrase “therapeutically effective amount” is meantto refer to an amount of therapeutic or prophylactic antibody that wouldbe appropriate to elicit the desired therapeutic or prophylactic effector response, including alleviating some or all of such symptoms ofdisease or reducing the predisposition to the disease, when administeredin accordance with the desired treatment regimen.

As used herein, an antibody “binds specifically to,” is “specificto/for” or “specifically recognizes” an antigen (here, PRLR) if such anantibody is able to discriminate between such antigen and one or morereference antigen(s), since binding specificity is not an absolute, buta relative property. In its most general form (and when no definedreference is mentioned), “specific binding” is referring to the abilityof the antibody to discriminate between the antigen of interest and anunrelated antigen, as determined, for example, in accordance with one ofthe following methods. Such methods comprise, but are not limited toWestern blots, ELISA-, RIA-, ECL-, IRMA-tests and peptide scans. Forexample, a standard ELISA assay can be carried out. The scoring may becarried out by standard color development (e.g. secondary antibody withhorseradish peroxide and tetramethyl benzidine with hydrogenperoxide).The reaction in certain wells is scored by the optical density, forexample, at 450 nm. Typical background (=negative reaction) may be 0.1OD; typical positive reaction may be 1 OD. This means the differencepositive/negative can be more than 10-fold. Typically, determination ofbinding specificity is performed by using not a single referenceantigen, but a set of about three to five unrelated antigens, such asmilk powder, BSA, transferrin or the like. However, “specific binding”also may refer to the ability of an antibody to discriminate between thetarget antigen and one or more closely related antigen(s), which areused as reference points. Additionally, “specific binding” may relate tothe ability of an antibody to discriminate between different parts ofits target antigen, e.g. different domains, subdomains or regions ofPRLR, such as epitopes in the N-terminal or in the C-terminal region ofthe ECD of PRLR, or between one or more key amino acid residues orstretches of amino acid residues of the ECD of PRLR.

“Affinity” or “binding affinity” K_(D) are often determined bymeasurement of the equilibrium association constant (ka) and equilibriumdissociation constant (kd) and calculating the quotient of kd to ka(K_(D)=kd/ka). The term “immunospecific” or “specifically binding” meansthat the antibody binds to PRLR or its ECD with an affinity K_(D) oflower than or equal to 10⁻⁶M (monovalent affinity). The term “highaffinity” means that the K_(D) that the antibody binds to PRLR or itsECD with an affinity K_(D) of lower than or equal to 10⁻⁷M (monovalentaffinity). The antibody may have substantially greater affinity for thetarget antigen compared to other unrelated molecules. The antibody mayalso have substantially greater affinity for the target antigen comparedto homologs, e.g. at least 1.5-fold, 2-fold, 5-fold 10-fold, 100-fold,10⁻³-fold, 10⁻⁴-fold, 10⁻⁵-fold, 10⁻⁶-fold or greater relative affinityfor the target antigen. Such affinities may be readily determined usingconventional techniques, such as by equilibrium dialysis; by using theBIAcore 2000 instrument, using general procedures outlined by themanufacturer; by radioimmunoassay using radiolabeled target antigen; orby another method known to the skilled artisan. The affinity data may beanalyzed, for example, by the method of Scatchard et al., Ann N.Y. Acad.ScL, 51:660 (1949).

As used herein the phrase “antibodies antagonize prolactin mediatedsignaling” is meant to refer to a blockade of prolactin receptoractivation by the antibodies of the present invention which leads to acomplete inhibition of prolactin receptor mediated signaling.

As used herein the phrase “antibodies compete for binding” is meant torefer to a competition between one antibody and a second antibody ormore antibodies for binding to the prolactin receptor.

The term “antibody” is used in the broadest sense and includes fullyassembled antibodies, monoclonal antibodies, polyclonal antibodies,multispecific antibodies (e.g., bispecific antibodies), antibodyfragments that can bind the antigen (e.g., Fab′, F′(ab)2, Fv, singlechain antibodies, diabodies), camel bodies and recombinant peptidescomprising the forgoing as long as they exhibit the desired biologicalactivity. Antibodies may carry different constant domains (Fc domains)on their heavy chain preferably derived from IgG1, IgG2, or IgG4isotypes (see below). Mutations for modification of effector functionsmay be introduced. Amino acid residues in the Fc-domain that play adominant role in the interactions with the complement protein C1q andthe Fc receptors have been identified and mutations influencing effectorfunctions have been described (for a review see Labrijn et al., Currentopinion in Immunology 20:479-485, 2008). Particularly, aglycosylation ofIgG1 may be achieved by mutating asparagine to alanine or asparagine toglutamine at amino acid position 297, which has been reported to abolishantibody-derived cell-mediated cytotoxicity (ADCC) (Sazinsky et al.,Proc. Nat. Acad. Sci. 105 (51): 20169, 2008; Simmons et al., J. ofImmunological Methods 263: 133-147, 2002). Replacement of lysine byalanine at position 322 leads to reduction of ADCC and removal ofcomplement-derived cytotoxicity (CDC), while simultaneous replacement ofthe two leucines at position 234 and 235 by alanines leads to avoidanceof ADCC and CDC [Hezareh et al., J. of Virology, 75 (24):12161-12168,2001]. In order to apply IgG4 isotypes as bivalent therapeutics in vivowhich retain avidity, a modification such as the serine-to-prolineexchange in the ‘core hinge region’ (Schuurman, J. et al. Immunology 97:693-698, 1999) may be introduced. The tendency of human IgG2 moleculesto form heterogeneous covalent dimers may be circumvented by exchangingone of the cysteines at position 127, 232 and 233 to serine (Allen etal., Biochemistry, 2009, 48 (17), pp 3755-3766). An alternative formatwith reduced effector function may be the IgG2m4 format, derived fromIgG2 carrying four IgG4-specific amino acid residue changes (An et al.,mAbs 1(6), 2009). Antibody fragments may be produced by recombinant DNAtechniques or by enzymatic or chemical cleavage of intact antibodies andare described further below. Nonlimiting examples of monoclonalantibodies include murine, chimeric, humanized, human, and HumanEngineered™ immunoglobulins, antibodies, chimeric fusion proteins havingsequences derived from immunoglobulins, or muteins or derivativesthereof, each described further below. Multimers or aggregates of intactmolecules and/or fragments, including chemically derivatized antibodies,are contemplated.

The term “monoclonal antibody” as used herein refers to an antibodyobtained from a population of substantially homogeneous antibodies,i.e., the individual antibodies comprising the population are identicalexcept for possible naturally occurring mutations that may be present inminor amounts. Monoclonal antibodies are highly specific, being directedagainst a single antigenic site. Furthermore, in contrast toconventional (polyclonal) antibody preparations that typically includedifferent antibodies directed against different determinants (epitopes),each monoclonal antibody is directed against a single determinant on theantigen. In addition to their specificity, the monoclonal antibodies areadvantageous in that they are synthesized by the homogeneous culture,uncontaminated by other immunoglobulins with different specificities andcharacteristics.

The modifier “monoclonal” indicates the character of the antibody asbeing obtained from a substantially homogeneous population ofantibodies, and is not to be construed as requiring production of theantibody by any particular method. For example, the monoclonalantibodies to be used may be made by the hybridoma method firstdescribed by Kohler et al., Nature, 256:495 [1975, or may be made byrecombinant DNA methods (see, e.g., U.S. Pat. No. 4,816,567). The“monoclonal antibodies” may also be recombinant, chimeric, humanized,human, Human Engineered™, or antibody fragments, for example.

An “immunoglobulin” or “native antibody” is a tetrameric glycoprotein.In a naturally-occurring immunoglobulin, each tetramer is composed oftwo identical pairs of polypeptide chains, each pair having one “light”(about 25 kDa) and one “heavy” chain (about 50-70 kDa). Theamino-terminal portion of each chain includes a “variable” region ofabout 100 to 110 or more amino acids primarily responsible for antigenrecognition. The carboxy-terminal portion of each chain defines aconstant region primarily responsible for effector function.Immunoglobulins can be assigned to different classes depending on theamino acid sequence of the constant domain of their heavy chains. Heavychains are classified as mu (μ), delta (Δ), gamma (γ), alpha (α), andepsilon (ε), and define the antibody's isotype as IgM, IgD, IgG, IgA,and IgE, respectively. Several of these may be further divided intosubclasses or isotypes, e.g. IgG1, IgG2, IgG3, IgG4, IgAI and IgA2.Different isotypes have different effector functions; for example, IgG1and IgG3 isotypes often have ADCC activity. Human light chains areclassified as kappa (K) and lambda (λ) light chains. Within light andheavy chains, the variable and constant regions are joined by a “J”region of about 12 or more amino acids, with the heavy chain alsoincluding a “D” region of about 10 more amino acids. See generally,Fundamental Immunology, Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, N.Y.(1989)).

A “functional fragment” or “antigen-binding antibody fragment” of anantibody/immunoglobulin hereby is defined as a fragment of anantibody/immunoglobulin (e.g., a variable region of an IgG) that retainsthe antigen-binding region. An “antigen-binding region” of an antibodytypically is found in one or more hypervariable region(s) of anantibody, i.e., the CDR-1, -2, and/or -3 regions; however, the variable“framework” regions can also play an important role in antigen binding,such as by providing a scaffold for the CDRs. Preferably, the“antigen-binding region” comprises at least amino acid residues 4 to 103of the variable light (VL) chain and 5 to 109 of the variable heavy (VH)chain, more preferably amino acid residues 3 to 107 of VL and 4 to 111of VH, and particularly preferred are the complete VL and VH chains[amino acid positions 1 to 109 of VL and 1 to 113 of VH, while numberingof amino acid positions occurs according to the Kabat database (Johnsonand Wu, Nucleic Acids Res., 2000, 28, 214-218]. A preferred class ofimmunoglobulins for use in the present invention is IgG.

The term “hypervariable” region refers to the amino acid residues of thevariable domains VH and VL of an antibody or functional fragment whichare responsible for antigen-binding. The hypervariable region comprisesamino acid residues from a “complementarity determining region” or CDR[i.e., residues 24-34 (LCDR1), 50- 56 (LCDR2) and 88-97 (LCDR3) in thelight chain variable domain and 29-36 (HCDR1), 48-66 (HCDR2) and 93-102(HCDR3) in the heavy chain variable domain as described in FIG. 12]and/or those residues from a hypervariable loop [i.e., residues 26-32(within LCDR1), 50-52 (within LCDR2) and 91-96 (within LCDR3) in thelight chain variable domain and 26-32 (within HCDR1), 53- 55 (withinHCDR2) and 96-101 (within HCDR3) in the heavy chain variable domain asdescribed by Chothia et al., J. Mol. Biol. 196: 901-917 (1987)].

Nonlimiting examples of antibody fragments include Fab, Fab′, F(ab′)2,Fv, domain antibody (dAb), complementarity determining region (CDR)fragments, single-chain antibodies (scFv), single chain antibodyfragments, diabodies, triabodies, tetrabodies, minibodies, linearantibodies (Zapata et al., Protein Eng., 8(10):1057-1062 (1995));chelating recombinant antibodies, tribodies or bibodies, intrabodies,nanobodies, small modular immunopharmaceuticals (SMIPs), anantigen-binding-domain immunoglobulin fusion protein, a camelizedantibody, a VHH containing antibody, or muteins or derivatives thereof,and polypeptides that contain at least a portion of an immunoglobulinthat is sufficient to confer specific antigen binding to thepolypeptide, such as a CDR sequence, as long as the antibody retains thedesired biological activity; and multispecific antibodies formed fromantibody fragments (C. A. K Borrebaeck, editor (1995) AntibodyEngineering (Breakthroughs in Molecular Biology), Oxford UniversityPress; R. Kontermann & S. Duebel, editors (2001) Antibody Engineering(Springer Laboratory Manual), Springer Verlag). An antibody other than a“bispecific” or “bifunctional” antibody is understood to have each ofits binding sites identical. The F(ab′)₂ or Fab may be engineered tominimize or completely remove the intermolecular disulphide interactionsthat occur between the C_(H1) and C_(L) domains. Papain digestion ofantibodies produces two identical antigen-binding fragments, called“Fab” fragments, each with a single antigen-binding site, and a residual“Fc” fragment, whose name reflects its ability to crystallize readily.Pepsin treatment yields an F(ab′)2 fragment that has two “Fv” fragments.An “Fv” fragment is the minimum antibody fragment that contains acomplete antigen recognition and binding site. This region consists of adimer of one heavy- and one light-chain variable domain in tight,non-covalent association. It is in this configuration that the threeCDRs of each variable domain interact to define an antigen binding siteon the surface of the VH-VL dimer. Collectively, the six CDRs conferantigen-binding specificity to the antibody. However, even a singlevariable domain (or half of an Fv comprising only three CDRs specificfor an antigen) has the ability to recognize and bind antigen.

“Single-chain Fv” or “sFv” or “scFv” antibody fragments comprise the VHand VL domains of antibody, wherein these domains are present in asingle polypeptide chain.

Preferably, the Fv polypeptide further comprises a polypeptide linkerbetween the VH and VL domains that enables the Fv to form the desiredstructure for antigen binding. For a review of sFv see Pluckthun in ThePharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Mooreeds., Springer-Verlag, New York, pp. 269-315 (1994).

The Fab fragment also contains the constant domain of the light chainand the first constant domain (CH1) of the heavy chain. Fab fragmentsdiffer from Fab′ fragments by the addition of a few residues at thecarboxy terminus of the heavy chain CH1 domain including one or morecysteines from the antibody hinge region. Fab′-SH is the designationherein for Fab′ in which the cysteine residue(s) of the constant domainsbear a free thiol group. F(ab′)2 antibody fragments originally wereproduced as pairs of Fab′ fragments which have hinge cysteines betweenthem.

“Framework” or FR residues are those variable domain residues other thanthe hypervariable region residues.

The phrase “constant region” refers to the portion of the antibodymolecule that confers effector functions.

The term “mutein” or “variant” can be used interchangeably and refers tothe polypeptide sequence of an antibody that contains at least one aminoacid substitution, deletion, or insertion in the variable region or theportion equivalent to the variable region, provided that the mutein orvariant retains the desired binding affinity or biological activity.

Muteins may be substantially homologous or substantially identical tothe parent antibody.

The term “derivative” refers to antibodies covalently modified by suchtechniques as ubiquitination, conjugation to therapeutic or diagnosticagents, labeling (e.g., with radionuclides or various enzymes), covalentpolymer attachment such as pegylation (derivatization with polyethyleneglycol) and insertion or substitution by chemical synthesis ofnon-natural amino acids.

A “human” antibody or functional human antibody fragment is herebydefined as one that is not chimeric or “humanized” and not from (eitherin whole or in part) a non-human species. A human antibody or functionalantibody fragment can be derived from a human or can be a synthetichuman antibody. A “synthetic human antibody” is defined herein as anantibody having a sequence derived, in whole or in part, in silico fromsynthetic sequences that are based on the analysis of known humanantibody sequences. In silico design of a human antibody sequence orfragment thereof can be achieved, for example, by analyzing a databaseof human antibody or antibody fragment sequences and devising apolypeptide sequence utilizing the data obtained therefrom. Anotherexample of a human antibody or functional antibody fragment is one thatis encoded by a nucleic acid isolated from a library of antibodysequences of human origin (i.e., such library being based on antibodiestaken from a human natural source). Examples of human antibodies includen-CoDeR-based antibodies as described by Carlsson and Soderlind Exp.Rev. Mol. Diagn. 1 (1), 102-108 (2001), Soderlin et al. Nat. Biotech.18, 852-856 (2000) and U.S. Pat. No. 6,989,250.

A “humanized antibody” or functional humanized antibody fragment isdefined herein as one that is (i) derived from a non-human source (e.g.,a transgenic mouse which bears a heterologous immune system), whichantibody is based on a human germline sequence; or (ii) CDR-grafted,wherein the CDRs of the variable domain are from a non-human origin,while one or more frameworks of the variable domain are of human originand the constant domain (if any) is of human origin.

The phrase “chimeric antibody,” as used herein, refers to an antibodycontaining sequence derived from two different antibodies (see, e.g.,U.S. Pat. No. 4,816,567) which typically originate from differentspecies. Most typically, chimeric antibodies comprise human and murineantibody fragments, generally human constant and mouse variable regions.

“Human Engineered™” antibodies generated by altering the parent sequenceaccording to the methods set forth in Studnicka et al., U.S. Pat. No.5,766,886 such as the antibody represented by SEQ ID NOs 58, 61, 64, 67and described in patent application WO008/022295.

An antibody of the invention may be derived from a recombinant antibodygene library. The development of technologies for making repertoires ofrecombinant human antibody genes, and the display of the encodedantibody fragments on the surface of filamentous bacteriophage, hasprovided a recombinant means for directly making and selecting humanantibodies, which also can be applied to humanized, chimeric, murine ormutein antibodies. The antibodies produced by phage technology areproduced as antigen binding fragments—usually Fv or Fab fragments—inbacteria and thus lack effector functions. Effector functions can beintroduced by one of two strategies: The fragments can be engineeredeither into complete antibodies for expression in mammalian cells, orinto bispecific antibody fragments with a second binding site capable oftriggering an effector function. Typically, the Fd fragment (VH-CH1) andlight chain (VL-CL) of antibodies are separately cloned by PCR andrecombined randomly in combinatorial phage display libraries, which canthen be selected for binding to a particular antigen. The Fab fragmentsare expressed on the phage surface, i.e., physically linked to the genesthat encode them. Thus, selection of Fab by antigen binding co-selectsfor the Fab encoding sequences, which can be amplified subsequently. Byseveral rounds of antigen binding and re-amplification, a proceduretermed panning, Fab specific for the antigen are enriched and finallyisolated.

A variety of procedures have been described for deriving humanantibodies from phage-display libraries. Such libraries may be built ona single master framework, into which diverse in vivo-formed (i. e.human-derived) CDRs are allowed to recombine as described by Carlssonand Soderlind Exp. Rev. Mol. Diagn. 1 (1), 102-108 (2001), Soderlin etal. Nat. Biotech. 18, 852-856 (2000) and U.S. Pat. No. 6,989,250.Alternatively, such an antibody library may be based on amino acidsequences that have been designed in silico and encoded by nucleic acidsthat are synthetically created. In silico design of an antibody sequenceis achieved, for example, by analyzing a database of human sequences anddevising a polypeptide sequence utilizing the data obtained therefrom.Methods for designing and obtaining in silico-created sequences aredescribed, for example, in Knappik et al., J. Mol. Biol. (2000) 296:57;Krebs et al., J. Immunol. Methods. (2001) 254:67; and U.S. Pat. No.6,300,064. For a review of phage display techniques, see WO08/022295(Novartis).

Alternatively, an antibody of this invention may come from animals. Suchan antibody may be humanized or Human Engineered summarized inWO08/022295 (Novartis); such an antibody may come from transgenicanimals [see also WO08/022295 (Novartis)].

As used herein, different ‘forms’ of antigen, e.g. PRLR, are herebydefined as different protein molecules resulting from differenttranslational and posttranslational modifications, such as, but notlimited to, differences in splicing of the primary prolactin receptortranscript, differences in glycosylation, and differences inposttranslational proteolytic cleavage.

As used herein, the term ‘epitope’ includes any protein determinantcapable of specific binding to an immunoglobulin or T-cell receptor.Epitopic determinants usually consist of chemically active surfacegroupings of molecules such as amino acids or sugar side chains andusually have specific three dimensional structural characteristics, aswell as specific charge characteristics. Two antibodies are said to‘bind the same epitope’ if one antibody is shown to compete with thesecond antibody in a competitive binding assay, by any of the methodswell known to those of skill in the art, and if preferably all aminoacids of the epitope are bound by the two antibodies.

The term ‘maturated antibodies’ or ‘maturated antigen-binding fragments’such as maturated Fab variants includes derivatives of an antibody orantibody fragment exhibiting stronger binding—i. e. binding withincreased affinity—to a given antigen such as the extracellular domainof the PRLR. Maturation is the process of identifying a small number ofmutations within the six CDRs of an antibody or antibody fragmentleading to this affinity increase. The maturation process is thecombination of molecular biology methods for introduction of mutationsinto the antibody and screening for identifying the improved binders.

Therapeutic Methods

Therapeutic methods involve administering to a subject in need oftreatment a therapeutically effective amount of an antibody contemplatedby the invention. A “therapeutically effective” amount hereby is definedas the amount of an antibody that is of sufficient quantity to blockproliferation of PRLR-positive cells in a treated area of a subjecteither as a single dose or according to a multiple dose regimen, aloneor in combination with other agents, which leads to the alleviation ofan adverse condition, yet which amount is toxicologically tolerable. Thesubject may be a human or non-human animal (e.g., rabbit, rat, mouse,monkey or other lower-order primate).

An antibody of the pharmaceutical composition of the invention might beco-administered with known medicaments, and in some instances theantibody might itself be modified. For example, an antibody could beconjugated to an immunotoxin or radioisotope to potentially furtherincrease efficacy.

The inventive antibodies can be used as a therapeutic or a diagnostictool in a variety of situations where PRLR is undesirably highlyexpressed. Disorders and conditions particularly suitable for treatmentwith an antibody of the inventions are endometriosis, adenomyosis,non-hormonal female fertility contraception, benign breast disease andmastalgia, lactation inhibition, benign prostate hyperplasia, fibroids,hyper- and normoprolactinemic hair loss, and cotreatment in combinedhormone therapy to inhibit mammary epithelial cell proliferation.

To treat any of the foregoing disorders, pharmaceutical compositions foruse in accordance with the present invention may be formulated in aconventional manner using one or more physiologically acceptablecarriers or excipients. An antibody of the invention can be administeredby any suitable means, which can vary, depending on the type of disorderbeing treated. Possible administration routes include parenteral (e.g.,intramuscular, intravenous, intraarterial, intraperitoneal, orsubcutaneous), intrapulmonary and intranasal, and, if desired for localimmunosuppressive treatment, intralesional administration. In addition,an antibody of the invention might be administered by pulse infusion,with, e.g., declining doses of the antibody. Preferably, the dosing isgiven by injections, most preferably intravenous or subcutaneousinjections, depending in part on whether the administration is brief orchronic. The amount to be administered will depend on a variety offactors such as the clinical symptoms, weight of the individual, whetherother drugs are administered. The skilled artisan will recognize thatthe route of administration will vary depending on the disorder orcondition to be treated.

Determining a therapeutically effective amount of the novel polypeptide,according to this invention, largely will depend on particular patientcharacteristics, route of administration, and the nature of the disorderbeing treated. General guidance can be found, for example, in thepublications of the International Conference on Harmonisation and inREMINGTON'S PHARMACEUTICAL SCIENCES, chapters 27 and 28, pp. 484-528(18th ed., Alfonso R. Gennaro, Ed., Easton, Pa.: Mack Pub. Co., 1990).More specifically, determining a therapeutically effective amount willdepend on such factors as toxicity and efficacy of the medicament.Toxicity may be determined using methods well known in the art and foundin the foregoing references. Efficacy may be determined utilizing thesame guidance in conjunction with the methods described below in theExamples.

Pharmaceutical Compositions and Administration

The present invention relates to pharmaceutical compositions which maycomprise one or more PRLR antibodies, alone or in combination with atleast one other agent, such as stabilizing compound, which may beadministered in any sterile, biocompatible pharmaceutical carrier,including, but not limited to, saline, buffered saline, dextrose, andwater. Any of these molecules can be administered to a patient alone, orin combination with other agents, drugs or hormones, in pharmaceuticalcompositions where it is mixed with excipient(s) or pharmaceuticallyacceptable carriers. In one embodiment of the present invention, thepharmaceutically acceptable carrier is pharmaceutically inert.

The present invention also relates to the administration ofpharmaceutical compositions. Such administration is accomplishedparenterally. Methods of parenteral delivery include topical,intra-arterial (directly to the tumor), intramuscular, subcutaneous,intramedullary, intrathecal, intraventricular, intravenous,intraperitoneal, intrauterine or intranasal administration. In additionto the active ingredients, these pharmaceutical compositions may containsuitable pharmaceutically acceptable carriers comprising excipients andauxilliaries which facilitate processing of the active compounds intopreparations which can be used pharmaceutically. Further details ontechniques for formulation and administration may be found in the latestedition of Remington's Pharmaceutical Sciences (Ed. Maack Publishing Co,Easton, Pa.).

Pharmaceutical formulations for parenteral administration includeaqueous solutions of active compounds. For injection, the pharmaceuticalcompositions of the invention may be formulated in aqueous solutions,preferably in physiologically compatible buffers such as Hank'ssolution, Ringer's solution, or physiologically buffered saline. Aqueousinjection suspensions may contain substances that increase viscosity ofthe suspension, such as sodium carboxymethyl cellulose, sorbitol, ordextran. Additionally, suspensions of the active compounds may beprepared as appropriate oily injection suspensions. Suitable lipophilicsolvents or vehicles include fatty oils such as sesame oil, or syntheticfatty acid esters, such as ethyl oleate or triglycerides, or liposomes.Optionally, the suspension may also contain suitable stabilizers oragents which increase the solubility of the compounds to allow for thepreparation of highly concentrated solutions.

For topical or nasal administration, penetrants appropriate to theparticular barrier to be permeated are used in the formulation. Suchpenetrants are generally known in the art.

Methods of parenteral delivery include topical, intra-arterial,intramuscular, subcutaneous, intramedullary, intrathecal,intraventricular, intravenous, intraperitoneal, vaginal, intrauterine,or intranasal administration

Kits

The invention further relates to pharmaceutical packs and kitscomprising one or more containers filled with one or more of theingredients of the afore mentioned pharmaceutical compositions of theinvention. Associated with such container(s) can be a notice in the formprescribed by a governmental agency regulating the manufacture, use orsale of pharmaceuticals or biological products, reflecting approval bythe agency of the manufacture, use or sale of the product for humanadministration.

In another embodiment, the kits may contain DNA sequences encoding theantibodies of the invention. Preferably the DNA sequences encoding theseantibodies are provided in a plasmid suitable for transfection into andexpression by a host cell. The plasmid may contain a promoter (often aninducible promoter) to regulate expression of the DNA in the host cell.The plasmid may also contain appropriate restriction sites to facilitatethe insertion of other DNA sequences into the plasmid to produce variousantibodies. The plasmids may also contain numerous other elements tofacilitate cloning and expression of the encoded proteins. Such elementsare well known to those of skill in the art and include, for example,selectable markers, initiation codons, termination codons, and the like.

Manufacture and Storage

The pharmaceutical compositions of the present invention may bemanufactured in a manner that is known in the art, e.g., by means ofconventional mixing, dissolving, granulating, dragee-making, levigating,emulsifying, encapsulating, entrapping or lyophilizing processes.

The pharmaceutical composition may be provided as a lyophilized powderin 1 mM-50 mM histidine, 0.1%-2% sucrose, 2%-7% mannitol at a pH rangeof 4.5 to 5.5 that is combined with buffer prior to use.

After pharmaceutical compositions comprising a compound of the inventionformulated in an acceptable carrier have been prepared, they can beplaced in an appropriate container and labeled for treatment of anindicated condition. For administration of PRLR antibodies, suchlabeling would include amount, frequency and method of administration.

Therapeutically Effective Dose

Pharmaceutical compositions suitable for use in the present inventioninclude pharmaceutical compositions wherein the active ingredients arecontained in an effective amount to achieve the intended purpose, i.e.treatment of a particular disease state characterized by PRLRexpression. The determination of an effective dose is well within thecapability of those skilled in the art.

For any compound, the therapeutically effective dose can be estimatedinitially either in cell culture assays, e.g., lymphoma cells, or inanimal models, usually mice, rats, rabbits, dogs, pigs or monkeys. Theanimal model is also used to achieve a desirable concentration range androute of administration. Such information can then be used to determineuseful doses and routes for administration in humans.

A therapeutically effective dose refers to that amount of protein or itsantibodies, antagonists, or inhibitors that ameliorate the symptoms orcondition. Therapeutic efficacy and toxicity of such compounds can bedetermined by standard pharmaceutical procedures in cell cultures orexperimental animals, e.g., ED₅₀ (the dose therapeutically effective in50% of the population) and LD₅₀ (the dose lethal to 50% of thepopulation). The dose ratio between therapeutic and toxic effects is thetherapeutic index, and it can be expressed as the ratio, ED₅₀/LD₅₀.Pharmaceutical compositions that exhibit large therapeutic indices arepreferred. The data obtained from cell culture assays and animal studiesare used in formulating a range of dosage for human use. The dosage ofsuch compounds lies preferably within a range of circulatingconcentrations what include the ED₅₀ with little or no toxicity. Thedosage varies within this range depending upon the dosage form employed,sensitivity of the patient, and the route of administration.

The exact dosage is chosen by the individual physician in view of thepatient to be treated. Dosage and administration are adjusted to providesufficient levels of the active moiety or to maintain the desiredeffect. Additional factors that may be taken into account include theseverity of the disease state, eg, size and location of endometrioticlesions; age, weight and gender of the patient; diet, time and frequencyof administration, drug combination(s), reaction sensitivities, andtolerance/response to therapy. Long acting pharmaceutical compositionsmight be administered every 3 to 4 days, every week, or once every twoweeks, or once within a month depending on half-life and clearance rateof the particular formulation.

Normal dosage amounts may vary from 0.1 to 100,000 micrograms, up to atotal dose of about 2 g, depending upon the route of administration.Guidance as to particular dosages and methods of delivery is provided inthe literature. See U.S. Pat. No. 4,657,760; U.S. Pat. No. 5,206,344; orU.S. Pat. No. 5,225,212. Those skilled in the art will employ differentformulations for polynucleotides than for proteins or their inhibitors.Similarly, delivery of polynucleotides or polypeptides will be specificto particular cells, conditions, locations, etc. Preferred specificactivities for for a radiolabeled antibody may range from 0.1 to 10mCi/mg of protein (Riva et al., Clin. Cancer Res. 5:3275s-3280s, 1999;Wong et al., Clin. Cancer Res. 6:3855-3863, 2000; Wagner et al., J.Nuclear Med. 43:267-272, 2002).

The present invention is further described by the following examples.The examples are provided solely to illustrate the invention byreference to specific embodiments. These exemplifications, whileillustrating certain specific aspects of the invention, do not portraythe limitations or circumscribe the scope of the disclosed invention.

All examples were carried out using standard techniques, which are wellknown and routine to those of skill in the art, except where otherwisedescribed in detail. Routine molecular biology techniques of thefollowing examples can be carried out as described in standardlaboratory manuals, such as Sambrook et al., Molecular Cloning: ALaboratory Manual, 2nd Ed.; Cold Spring Harbor Laboratory Press, ColdSpring Harbor, N.Y., 1989.

DESCRIPTION OF THE FIGURES

FIG. 1: Expression of prolactin-mRNA (PRL-mRNA) (analyzed by real-timeTaqMan PCR analysis) in human endometrium and lesions (ectopic tissue)from healthy women and women suffering from endometriosis.

FIG. 2: Expression of prolactin receptor-mRNA (PRLR-mRNA) (analyzed byreal-time TaqMan PCR analysis) in human endometrium and lesions (ectopictissue) from healthy women and women suffering from endometriosis.

FIG. 3: Northern blot analysis of PRLR gene expression in rat tissues.Gene expression of the PRLR revealed high expression in placenta andprostate.

FIG. 4: Western blot analysis of PRLR expression in rat prostatestreated with different hormones. Estradiol treatment of intact rats andcastration lead to an upregulation of PRLR protein in rat prostateswhereas dihydrotestosterone treatment of intact rats had no impact onPRLR expression in the prostate compared to vehicle treatment of intactanimals.

FIG. 5: Inhibition of prolactin-activated Ba/F (=Baf) cell proliferation(stably expressing the human PRLR) by neutralizing PRLR antibodies andunspecific control antibodies. The IC₅₀ values were determined for thefollowing antibodies in IgG1 format: 005-C04 (closed circles): 1.29μg/ml=8.6 nM; 006-H08 (open circles): 0.15 μg/ml=1 nM; HE06.642 (closedtriangles): 0.34 μg/ml=2.2 nM; 002-H06 (open triangles): 0.54 μg/ml=3.6nM; 002-H08 (closed squares): 0.72 μg/ml=4.8 nM; unspecific controlantibody (open squares): no inhibition of cell proliferation

FIG. 6: Inhibition of prolactin-induced rat lymphoma cell proliferation(NB2 cells) by neutralizing PRLR antibodies and unspecific controlantibodies. The following IC₅₀ values were determined: XHA06.642 (closedcircles): 10 μg/ml=67 nM; XHA06.983 (open circles): no effect on ratlymphoma cell proliferation; unspecific control antibody (closedtriangle): no effect at 10 μg/ml.

FIG. 7: Inhibition of prolactin-stimulated STAT5 phosphorylation in T47Dcells by neutralizing PRLR antibodies and unspecific control antibody.

The unspecific control antibody (FITC) does not inhibit STAT5phosphorylation in T47D cells. In contrast the antibodies XHA06.642,005-C04 (=IgG1 005-C04), and 006-H08 (=IgG1 006-H08) inhibit in adose-dependent manner phosphorylation of STAT5 in T47D cells.

FIG. 8: Effects of neutralizing PRLR antibodies and unspecific controlson prolactin-activated luciferase reporter gene activity using HEK293cells stably transfected with the human prolactin receptor (hPRLR) andtransiently expressing the luciferase gene under the control oflactogenic hormone response elements (LHREs). The IC₅₀ values weredetermined for the following antibodies in IgG1 format: 006-H08 (closedcircles): 0.83 μg/ml=5.5 nM; HE06.642 (open circles): 0.63 μg/ml=4.2 nM;unspecific control antibody (closed triangle): no inhibition ofluciferase activity.

FIG. 9: Effects of neutralizing PRLR antibodies and unspecific controlson prolactin-activated luciferase reporter gene activity using HEK293cells stably transfected with the murine prolactin receptor (mPRLR) andtransiently expressing the luciferase gene under the control oflactogenic hormone response elements (LHREs). The IC₅₀ values weredetermined for the following antibodies in IgG1 format: 005-C04 (closedtriangles): 0.45 mg/ml=3 nM; XHA06.642 (closed circles):>>50 μg/ml>>333nM, unspecific control antibody (open circles): no inhibition ofluciferase activity.

FIG. 10: Inhibition of prolactin-activated Ba/F (=Baf) cellproliferation (stably expressing the murine prolactin receptor) byneutralizing prolactin receptor antibodies and unspecific controlantibodies. The IC₅₀ values were determined for the following antibodiesin IgG1 format: unspecific FITC antibody (closed squares): no inhibitionof cell proliferation; HE06.642 (closed circles):>>>30 μg/ml>>>200 nM;001-E06 (open circles): 43.7 μg/ml=291 nM; 001-D07 (closed triangles):16.5 μg/ml=110 nM; 005-C04 (open triangles): 0.74 μg/ml=4.9 nM.

FIG. 11: Pregnancy rates and mean litter size in female mice treatedwith phosphate-buffered saline (=vehicle), unspecific control antibody(FITC IgG1) or neutralizing antibody IgG1 005-C04 (=005-C04). Pregnancyrates were 87.5% (vehicle treated females), 75% (females treated with 10mg/kg unspecific antibody), 100% (females treated with 10 mg/kg IgG1005-C04), and 0% (females treated with 30 mg/kg IgG1 005-C04). Meanlitter size was 10.9 animals (vehicle treated females), 12.3 animals(females treated with 10 mg/kg unspecific antibody), 13 animals (femalestreated with 10 mg/kg IgG1 005-C04) and 0 animals (females treated with30 mg/kg IgG1 005-C04).

FIG. 12: Kabat Numbering of framework amino acid positions according toJohnson and Wu (Nucleic Acids Res. 2000, 28, 214-218).

FIG. 13: FACS analysis results with selected anti-PRLR antibodies(005-C04, 001-E06, HE06642). Binding of the antibodies was determined ata fixed concentration on HEK293 cells expressing the human and mousePRLR in comparison to the parental cell line not expressing PRLR.

FIG. 14A: Litter weight gain for each postpartal day expressed aspercentage of litter weight obtained on postpartal day 1. Weight gain oflitters from untreated mothers (closed circles), from mothers treatedwith 10 mg/kg unspecific murine IgG2a antibody (open circles), and frommothers treated with the neutralizing antibody 005-C04 containing murineIgG2a constant domains (=IgG2a 005-C04) at 10 mg/kg (closed triangles)and at 30 mg/kg (open triangles) is shown. Arrows indicate days on whichantibody injection was performed. There is a significant reduction inweight gain from litters of mothers treated with 30 mg/kg IgG2a 005-C04from postpartal day 8 onwards.

FIG. 14B: Incremental litter weight gain from day to day expressed aspercentage of litter weight on postpartal day 1. Results from litters ofuntreated mothers (closed circles), mothers treated with 10 mg/kgunspecific murine IgG2a antibody (open circles), mothers treated withthe neutralizing antibody 005-C04 containing murine IgG2a constantdomains (=IgG2a 005-C04) at 10 mg/kg (closed triangles) and at 30 mg/kg(open triangles) are shown. Basically FIG. 14A presents the slope of thegraphs shown in FIG. 14A. Daily weight gain in litters from untreatedmothers and mothers treated with 10 mg/kg unspecific antibody oscillatesaround 30% of the litter weight on postpartal day 1. In contrast,treatment of mothers with 30 mg/kg IgG2a 005-C04 leads to a significantreduction in weight gain from day 7 onwards (*p<0.05;***p<0.005 vs.litters from mothers treated with unspecific antibody) whereas treatmentwith 10 mg/kg IgG2a 005-C04 leads to a significant reduction in dailyweight gain from day 11 onwards (p<0.05 vs. litters from mothers treatedwith unspecific antibody). Arrows indicate days of antibody application.

FIG. 14C: Histological sections from mammary glands of lactatingmothers. Mammary glands from untreated mothers or mothers treated withunspecific antibody are filled with ducts producing milk. In contrastmammary gland involution, evidenced by the appearance of fatty islands(black arrows), is induced dose-dependently by the neutralizing IgG2a005-C04 antibody.

FIG. 14D: Milk protein expression in mammary glands from lactatingmothers. Expression of the milk proteins beta casein (Csn-2), wheyacidic protein (WAP), and IGF-1 is reduced in a dose-dependent manner inmothers treated with neutralizing PRLR antibody IgG2a 005-C04, but notwith unspecific antibodies. Gene expression was normalized to theexpression of TATA box binding protein (TBP).

FIG. 15A: Formation of side branches and alveolar like structures in ahyperprolactinemic mouse model of benign breast disease. Theneutralizing PRLR antibody IgG1 005-C04 (=005-C04) inhibits sidebranching and the formation of alveolar like structures at 10 and 30mg/kg in mice that received a pituitary isograft.

FIG. 15B: Extent of epithelial hyperplasia and epithelial cellproliferation in a hyperprolactinemic mouse model of benign breastdisease. Some BrdU-positive cells are marked by white arrows. Theneutralizing PRLR antibody IgG1 005-C04 (=005-C04) blocks epithelialhyperplasia and epithelial cell proliferation in the mammary gland.

FIG. 15C: Extent of STAT5 phosphorylation in a hyperprolactinemic mousemodel of benign breast disease. Some phospho-STAT5-positive cells areindicated by white arrows. The neutralizing PRLR antibody IgG1 005-C04(=005-C04) completely blocks STAT5 phosphorylation when applied at adosage of 30 mg/kg.

FIG. 16: Inhibition of prostate growth by the neutralizing PRLR antibody005-C04 containing murine IgG2a constant domains (=IgG2a 005-C04).Pituitary isografting stimulates prostate growth in comparison tountreated sham-operated mice. Treatment with neutralizing PRLRantibodies at doses of 10 mg/kg and at doses of 30 mg/kg inhibitsprostate growth (***p<0.005 vs. untreated, sham-operated mice).

FIG. 17: Neutralizing PRLR antibodies stimulate hair growth in thepresence of hyperprolactinemia. Photographs were taken three weeks afterpituitary isografting (and shaving) from male mice used in theexperiments described in Example 17 and in FIG. 16. Hyperprolactinemiainhibits hair regrowth in the shaved areas. Neutralizing PRLRantibodies, but not unspecific antibodies stimulate hair regrowth underhyperprolactinemic conditions at doses of 10 and 30 mg/kg of 005-C04(=IgG2a 005-C04).

FIG. 18: Neutralizing PRLR antibodies but not unspecific antibodiesstimulate hair regrowth in shaved areas in hyper- and normoprolactinemicmale and female mice. (Example 18). Neutralizing PRLR antibodies aretherefore suitable for the treatment of hair loss under normo- andhyperprolactinemic conditions in men (FIG. 18B) and women (FIG. 18A).

FIG. 19: Neutralizing PRLR antibodies but not unspecific controlantibodies inhibit enhanced epithelial cell proliferation in the mammarygland after combined hormone therapy, i.e. combined estrogen plusprogestin therapy.

The absolute number of proliferating ductal epithelial cells within 4cross-sections of the mammary gland was evaluated and the medians aredepicted as horizontal bars within the figure. Epithelial cellproliferation in ovariectomized, vehicle treated mice is rather low(median=0). Estradiol treatment leads to some stimulation of epithelialcell proliferation (median=9), maximal mammary epithelial cellproliferation is observed under estrogen plus progesterone treatment(median=144). Treatment with neutralising prolactin receptor antibody005-C04(median=84 after treatment with 10 mg/kg 005-C04; median=27 aftertreatment with 30 mg/kg 005-C04) but not with unspecific controlantibody (median=154) leads to a dose-dependent decrease in mammaryepithelial cell proliferation almost back to estradiol-only levels.Neutralising PRLR antibodies are therefore suitable to treat enhancedmammary epithelial cell proliferation under combined hormone therapy,i.e. estradiol plus progesterone treatment.

FIG. 20: Neutralizing PRLR antibodies but not unspecific controlantibodies inhibit endometriosis interna in mice. The results aredepicted as disease scores as described in Example 20. The mediandisease score for each experimental group is indicated as a horizontalbar. Normoprolactinemic mice develop endometriosis interna to somedegree (median disease score=0.25). Hyperprolactinemia due to pituitaryisografting enhances the disease score and more animals suffer from thedisease (median disease score=2.5). Whereas treatment with 30 mg/kgunspecific antibody once (median score=2.5) or twice (median score=2)weekly had no influence on the disease, treatment with specificneutralizing antibodies shows a dose-dependent decrease in the amount ofsick animals; the median disease score in all cases in which specificantibody was used was zero. Notably, all animals receiving either 10 or30 mg/kg specific antibody twice weekly were completely cured and theirdisease score was significantly lower than the disease score ofnormoprolactinemic mice. Neutralising PRLR antibodies are thereforesuitable to treat endometriosis interna (=adenomyosis uteri) andendometriosis externa in women.

Seq ID NO:1 represents amino acid sequence of HCDR1, 006-H08

Seq ID NO:2 represents amino acid sequence of HCDR1, 002-H06

Seq ID NO:3 represents amino acid sequence of HCDR1, 002-H08

Seq ID NO:4 represents amino acid sequence of HCDR1, 006-H07

Seq ID NO:5 represents amino acid sequence of HCDR1, 001-E06

Seq ID NO:6 represents amino acid sequence of HCDR1, 005-C04

Seq ID NO:7 represents amino acid sequence of HCDR2, 006-H08

Seq ID NO:8 represents amino acid sequence of HCDR2, 002-H06

Seq ID NO:9 represents amino acid sequence of HCDR2, 002-H08

Seq ID NO:10 represents amino acid sequence of HCDR2, 006-H07

Seq ID NO:11 represents amino acid sequence of HCDR2, 001-E06

Seq ID NO:12 represents amino acid sequence of HCDR2, 005-C04

Seq ID NO:13 represents amino acid sequence of HCDR3, 006-H08, 002-H06

Seq ID NO:14 represents amino acid sequence of HCDR3, 002-H08

Seq ID NO:15 represents amino acid sequence of HCDR3, 006-H07

Seq ID NO:16 represents amino acid sequence of HCDR3, 001-E06

Seq ID NO:17 represents amino acid sequence of HCDR3, 005-C04

Seq ID NO:18 represents amino acid sequence of LCDR1, 006-H08

Seq ID NO:19 represents amino acid sequence of LCDR1, 002-H06

Seq ID NO:20 represents amino acid sequence of LCDR1, 002-H08

Seq ID NO:21 represents amino acid sequence of LCDR1, 006-H07

Seq ID NO:22 represents amino acid sequence of LCDR1, 001-E06

Seq ID NO:23 represents amino acid sequence of LCDR1, 005-C04

Seq ID NO:24 represents amino acid sequence of LCDR2, 006-H08, 002-H08

Seq ID NO:25 represents amino acid sequence of LCDR2, 002-H06

Seq ID NO:26 represents amino acid sequence of LCDR2, 006-H07

Seq ID NO:27 represents amino acid sequence of LCDR2, 001-E06

Seq ID NO:28 represents amino acid sequence of LCDR2, 005-C04

Seq ID NO:29 represents amino acid sequence of LCDR3, 006-H08

Seq ID NO:30 represents amino acid sequence of LCDR3, 002-H06, 001-E06

Seq ID NO:31 represents amino acid sequence of LCDR3, 002-H08

Seq ID NO:32 represents amino acid sequence of LCDR3, 006-H07

Seq ID NO:33 represents amino acid sequence of LCDR3, 005-C04

Seq ID NO:34 represents amino acid sequence of VH, 006-H08

Seq ID NO:35 represents amino acid sequence of VH, 002-H06

Seq ID NO:36 represents amino acid sequence of VH, 002-H08

Seq ID NO:37 represents amino acid sequence of VH, 006-H07

Seq ID NO:38 represents amino acid sequence of VH, 001-E06

Seq ID NO:39 represents amino acid sequence of VH, 005-C04

Seq ID NO:40 represents amino acid sequence of VL, 006-H08

Seq ID NO:41 represents amino acid sequence of VL, 002-H06

Seq ID NO:42 represents amino acid sequence of VL, 002-H08

Seq ID NO:43 represents amino acid sequence of VL, 006-H07

Seq ID NO:44 represents amino acid sequence of VL, 001-E06

Seq ID NO:45 represents amino acid sequence of VL, 005-C04

Seq ID NO:46 represents nucleic acid sequence VH, 006-H08

Seq ID NO:47 represents nucleic acid sequence VH, 002-H06

Seq ID NO:48 represents nucleic acid sequence VH, 002-H08

Seq ID NO:49 represents nucleic acid sequence VH, 006-H07

Seq ID NO:50 represents nucleic acid sequence VH, 001-E06

Seq ID NO:51 represents nucleic acid sequence VH, 005-C04

Seq ID NO:52 represents nucleic acid sequence VL, 006-H08

Seq ID NO:53 represents nucleic acid sequence VL, 002-H06

Seq ID NO:54 represents nucleic acid sequence VL, 002-H08

Seq ID NO:55 represents nucleic acid sequence VL, 006-H07

Seq ID NO:56 represents nucleic acid sequence VL, 001-E06

Seq ID NO:57 represents nucleic acid sequence VL, 005-C04

Seq ID NO:58 represents amino acid sequence of VH, HE06642, Novartis(WO2008/22295)

Seq ID NO:59 represents amino acid sequence of VH, XHA06642, Novartis(WO2008/22295)

Seq ID NO:60 represents amino acid sequence of VH, XHA06983, Novartis(WO2008/22295)

Seq ID NO:61 represents amino acid sequence of VL, HE06642

Seq ID NO:62 represents amino acid sequence of VL, XHA06642 Novartis(WO2008/22295)

Seq ID NO:63 represents amino acid sequence of VL, XHA06983 Novartis(WO2008/22295)

Seq ID NO:64 represents nucleic acid sequence VH, HE06642

Seq ID NO:65 represents nucleic acid sequence VH, XHA06642 Novartis(WO2008/22295)

Seq ID NO:66 represents nucleic acid sequence VH, XHA06983 Novartis(WO2008/22295)

Seq ID NO:67 represents nucleic acid sequence VL, HE06642

Seq ID NO:68 represents nucleic acid sequence VL, XHA06642, Novartis(WO2008/22295)

Seq ID NO:69 represents nucleic acid sequence VL, XHA06983, Novartis(WO2008/22295)

Seq ID NO:70 represents human ECD_PRLR, amino acid position 1-210, 51domain 1-100 (S1 domain construct 1-102), S2 domain 101-210

Seq ID NO:71 represents CDS human ECD_PRLR, nucleotide position 1-630

Seq ID NO:72 represents murine ECD_PRLR, amino acid position 1-210

Seq ID NO:73 represents CDS murine ECD_PRLR, nucleotide position 1-630

EXAMPLES Example 1 Isolation of Target-Specific Antibodies from HumanAntibody Phage Display Libraries

To isolate a panel of antibodies able to neutralize the activity ofhuman PRLR, three human antibody phage display libraries, expressing Faband scFv fragments, were investigated in parallel. The target used forthe library panning was the soluble extracellular domain (ECD) of theprolactin receptor (human prolactin receptor amino acids 25-234)prepared as described above in WO08/022295 (Novartis). Alternativetargets were the ECD of PRLR C-terminally linked to six histidines or toa human IgG1-Fc domain via the linker with the amino acid sequence“isoleucine-glutamate-glycine-arginine-methionine-aspartate”.

Selection of target-specific antibodies from phage display was carriedout according to methods described by Marks et al. (Methods Mol Biol.248:161-76, 2004). Briefly, the phage display library was incubated with50 pmols of the biotinylated ECD at room temperature for 1 hr and thecomplex formed was then captured using 100 μl of Streptavidin beadssuspension (Dynabeads® M-280 Streptavidin, Invitrogen). Non specificphages were removed by washing the beads with wash buffer (PBS+5% Milk).Bound phages were eluted with 0.5 ml of 100 nM Triethylamine (TEA) andimmediately neutralized by addition of an equal volume of IM TRIS-Cl pH7.4. Eluted phage pool was used to infect TG1 E coli cells growing inlogarithmic phase, and phagemid was rescued as described (Methods MolBiol. 248:161-76, 2004). Selection was repeated for a total of threerounds. Single colonies obtained from TG1 cells infected with elutedphage from the third round of panning were screened for binding activityin an ELISA assay. Briefly, single colonies obtained from the TG1 cellinfected with eluted phage were used to inoculate media in 96-wellplates.

Microcultures were grown to an OD_(60O)=0.6 at which point expression ofsoluble antibody fragment was induced by addition of 1 mM IPTG followingovernight culture in a shaker incubator at 30° C. Bacteria were spundown and periplasmic extract was prepared and used to detect antibodybinding activity to ECD immobilized on 96-well microplates (96-well flatbottom lmmunosorb plates, Nunc) following standard ELISA protocolprovided by the microplate manufacturer.

The affinities of the anti-Prolactin Receptor (PRLR) antibodies forbinding to the recombinant extracellular domain (ECD) were estimatedusing the Biacore® 2000 and used for affinity ranking of antibodies.

Example 2 Quantitative Analysis of Prolactin and Prolactin Receptor GeneExpression by Real-Time TaqMan PCR Analysis in eu- and EctopicEndometrium and Endometriotic Lesions from Patients and Healthy Controls

Real-timeTaqman PCR analysis was performed using the ABI Prism 7700Sequence Detector System according to the manufacturer's instructions(PE Applied Biosystems) and as described (Endocrinolgy 2008, 149(8):3952-3959) and known by the expert in the field. Relative expressionlevels of PRL and the PRLR were normalized to the expression ofcyclophyllin. We analyzed the expression of PRL and the PRLR in theendometrium from healthy women and in endometrium and endometrioticlesions from patients by using quantitative real-time Taqman PCRanalysis. The expression of prolactin and its receptor was clearlyupregulated in endometriotic lesions compared to healthy endometrium orendometrium derived from patients. Results are shown in FIGS. 1 and 2.

These findings imply that autocrine prolactin signaling plays a role inthe development and maintenance of endometriosis and adenomyosis uteri(endometriosis interna, a form of endometriosis restricted to theuterus).

Example 3 Analysis of Prolactin Receptor Expression in Human Tissues byNorthern Blot

RNA was isolated from different rat tissues and transferred to a nylonmembrane after gel electrophoresis. The membranes were successivelyhybridized with radioactive labelled cDNAs for the rat prolactinreceptor or β-actin (as loading control), washed, and exposed to film.The bands correspond to the mRNAs for the rat prolactin receptor andβ-actin. The results shown in FIG. 3 indicate a strong expression of theprolactin receptor in the placenta, the prostate, the ovary and theadrenal gland.

Example 4 Regulation of Prolactin Receptor Protein Expression in RatProstate—Influence of Castration and Hormonal Treatments

Rats were either castrated or remained intact. Intact animals weretreated daily for 14 days with vehicle (intact), DHT (3 mg/kg), or E2(0.4 mg/kg). Afterwards prostates were isolated from animals of alltreatment groups and protein extracts were prepared. Protein extractswere separated by gel electrophoresis and transferred to a membrane. Theprolactin receptor was detected using the commercially availableantibody MA610 (Santa Cruz Biotechnology). The results are shown in FIG.4 and indicate the hormonal regulation of the prolactin receptor in therat prostate.

Example 5 Inhibition of Prolactin-Induced Proliferation of BaF3 Cells(Stably Transfected with Human Prolactin Receptor) by NeutralizingProlactin Receptor Antibodies and Unspecific Control Antibodies

To analyze the in vitro efficacy of the neutralizing PRLR antibodies,the inhibition of prolactin-activated cellular proliferation of BaF3cells was used. The cells were stably transfected with human PRLR andwere routinely cultured in RPMI containing 2 mM glutamine in thepresence of 10% FCS and 10 ng/ml of human prolactin. After six hours ofstarvation in prolactin-free medium containing 1% FCS, cells were seededinto 96-well plates at a density of 10000 cells per well. Cells werestimulated with 20 ng/ml prolactin and coincubated with increasing dosesof neutralizing PRLR antibodies for two days. Cellular proliferation wasanalyzed using a CellTiter-Glo Luminescent Cell Viability Assay(Promega). Dose-response curves for the inhibition ofprolactin-stimulated cellular growth were generated and IC₅₀ valuescalculated. As negative control, stimulation with an unspecific controlantibody was used.

The dose-response curves and IC₅₀ values are depicted in FIG. 5. Theunspecific antibody did not inhibit the proliferation of BaF cellsstably expressing the human PRLR, whereas the specific antibodiesblocked cell proliferation and exhibited different potencies.Neutralizing antibody 006-H08 showed the highest potency in this readoutparadigm.

Example 6 Inhibition of Prolactin-Induced Rat Lymphoma CellProliferation by Specific and Unspecific Antibodies

The in vitro efficacy of the neutralizing PRLR antibodies was alsotested using inhibition of prolactin-dependent rat lymphoma cell (Nb2-11cells) proliferation. Nb2-11 cells were routinely grown in RPMIcontaining 10% FCS and 10% horse serum. Before starting cellular growthassays, cells were grown for 24 hours in the same medium containing 1%FCS instead of 10% FCS. Afterwards, cells were seeded in 96-well platesin FCS-free medium at a density of 10000 cells per well. Cells werestimulated with 10 ng/ml human prolactin in the presence or absence ofincreasing doses of neutralizing PRLR antibodies or control antibodiesfor 2 days. Afterwards cellular proliferation was assessed using aCellTiter-Glo Luminescent Cell Viability Assay (Promega). Dose-responsecurves and IC₅₀ values are depicted in FIG. 6. The unspecific antibodyand antibody XHA06.983, that does not bind the rat PRLR, did not blockNb2-11 cell proliferation. XHA06.642 which binds the rat PRLR blockedNb2-11 cell proliferation.

Example 7 Inhibition of Prolactin-Induced STAT5 Phosphorylation in T47DCells by Neutralizing Prolactin Receptor Antibodies

To analyze the in vitro efficacy of the neutralizing PRLR antibodies inan additional readout, the inhibition of STAT5 phosphorylation in humanT47D cells treated with prolactin was used. T47D cells were grown inRPMI containing 10% FCS and 2 mM glutamine. Cells were seeded on 24-wellplates at a density of 0.5×10⁵ cells per well.

The next day, cells were starved for 1 h in serum free RPMI. Afterwardscells were incubated with or without different doses of neutralizingPRLR antibodies or unspecific control antibody in the absence orpresence of 20 ng/ml human prolactin for 30 min. Afterwards cells wererinsed and lysed in 70 μl of lysisbuffer. Lysates were centrifuged andthe supernatant was frozen at −80° C. Extracts were analyzed usingWestern blot (anti-pSTAT5A/B antibody from upstate 07-586, 1:1000diluted). As loading control the stripped blots were incubated withanti-beta tubulin antibody (ab7287, 1:500 diluted). Results are shown inFIG. 7. With the exception of the unspecific FITC antibody, allneutralizing PRLR antibodies blocked STAT5 phosphorylation in human T47Dcells dose-dependently. All tested antibodies bound to the human PRLRwith high affinity.

Example 8 Inhibition of Luciferase Reporter Gene Activity in Hek293Cells Stably Transfected with the Human PRLR—Analysis of NeutralizingProlactin Receptor Antibodies and Unspecific Control Antibodies

To further analyze the in vitro efficacy of the neutralizing PRLRantibodies, a reporter gene assay was used. HEK293HEK293 cells stablytransfected with the human PRLR were transiently transfected with aluciferase reporter gene under the control of LHREs (lactogenic hormoneresponse elements) for 7 hours. Afterwards, cells were seeded at adensity of 20000 cells per well on a 96-well plate (0.5% charcoalstripped serum, DMEM). The next day 300 ng/ml human prolactin with andwithout increasing doses of neutralizing PRLR antibodies or controlantibodies was added. 24 hours later, luciferase activity wasdetermined. Results are depicted in FIG. 8. In contrast to theunspecific antibody, 006-H08 and HE06.642 inhibited luciferase activityin HEK293 cells stably transfected with the human PRLR.

Example 9 Inhibition of Luciferase Reporter Gene Activity in Hek293Cells Stably Transfected with the Murine PRLR—Analysis of NeutralizingProlactin Receptor Antibodies and Unspecific Control Antibodies

To further analyze the in vitro efficacy of the neutralizing PRLRantibodies on the murine prolactin receptor, a reporter gene assay wasused. HEK293 cells stably transfected with the murine PRLR weretransiently transfected with a luciferase reporter gene under thecontrol of LHREs (lactogenic hormone response elements) for 7 hours.Afterwards, cells were seeded at a density of 20000 cells per well on a96-well plate (0.5% charcoal stripped serum, DMEM). The next day 200ng/ml human prolactin with and without increasing doses of neutralizingPRLR antibodies or control antibodies was added. 24 hours later,luciferase activity was determined. Results are depicted in FIG. 9.Whereas the antibody 005-C04 (closed triangles) exhibits high activity(IC₅₀ value =3 nM), the antibody HE06.642 (closed circles) does not showactivity up to 330 nM. The unspecific control antibody (open circles) iscompletely inactive. In contrast to the Novartis antibody HE06.642, theantibody 005-C04 is able to block murine PRLR-mediated signaling.

Example 10 Inhibition of Prolactin-Induced Proliferation of BaF3 Cells(Stably Transfected with the Murine Prolactin Receptor) by NeutralizingProlactin Receptor Antibodies and Unspecific Control Antibodies

To analyze the in vitro efficacy of the neutralizing PRLR antibodies,the inhibition of prolactin-activated cellular proliferation of Ba/F3cells was used. The cells were stably transfected with the murine PRLRand were routinely cultured in RPMI containing 2 mM glutamine in thepresence of 10% FCS and 10 ng/ml of human prolactin. After six hours ofstarvation in prolactin-free medium containing 1% FCS, cells were seededinto 96-well plates at a density of 10000 cells per well. Cells werestimulated with 40 ng/ml prolactin and coincubated with increasing dosesof neutralizing PRLR antibodies for two days. Cellular proliferation wasanalyzed using a CellTiter-Glo Luminescent Cell Viability Assay(Promega). Dose-response curves for the inhibition ofprolactin-stimulated cellular growth were generated and IC₅₀ valuescalculated. As negative control, stimulation with an unspecific controlantibody was used.

The dose-response curves and IC₅₀ values are depicted in FIG. 10. Theunspecific control antibody (closed squares) was inactive at the murinePRLR. There was only limited inhibition of murine PRLR activation by theantibodies HE06.642, 001-E06, and 001-D07. Only antibody 005-C04completely blocked murine PRLR activation.

Example 11 Contraceptive Effect of Neutralizing Prolactin ReceptorAntibody IgG1 005-C04in Mice

To test the influence of neutralizing prolactin receptor antibodies onfertility in mice, 12 week old female and male NMRI mice were mated for7 days (day 0-day 7). Female mice were treated on days -3, 0, 3, and 6with an intraperitoneal injection of either phosphate-buffered saline,unspecific IgG1 control antibody (anti-FITC, 10 mg/kg), or theneutralizing IgG1 antibody 005-C04 (=IgG1 005-C04) at concentrations of10 or 30 mg per kg body weight dissolved in phosphate buffered saline.10 females were used in each experimental group. Each male was matedwith two females, one of the females was from a negative control grouptreated with either phosphate-buffered saline or unspecific antibody,the other female was treated with specific neutralizing antibody.Matings, in which the male did not produce at least one pregnant female,were excluded from data evaluation. Readout parameters were mean littersize and pregnancy rates (measured in %) calculated as litter number perexperimental group divided by the number of theoretical possible litterswithin this group. Results are depicted in FIG. 11.

FIG. 11A shows the obtained pregnancy rates. Pregnancy rates were asfollows:

-   -   87.5% in the group of mice treated with phosphate buffered        saline,    -   75% in the group of mice treated with the unspecific control        antibody (10 mg/kg),    -   100% in the group of mice treated with the neutralizing PRLR        antibody IgG1 005-C04 (10 mg/kg), and    -   0% in the group of mice treated with the neutralizing PRLR        antibody IgG1 005-C04 (30 mg/kg).

FIG. 11 B shows the observed litter sizes for the different experimentalgroups. Litter sizes were as follows:

10.9 mice per litter in the group of mice treated with phosphatebuffered saline,

12.3 mice per litter in the group of mice treated with the unspecificcontrol antibody (10 mg/kg),

13 mice per litter in the group of mice treated with the neutralizingPRLR antibody IgG1 005-C04 (10 mg/kg), and

0 mice per litter in the group of mice treated with the neutralizingPRLR antibody IgG1 005-C04 (30 mg/kg).

The results from this mating study demonstrate that the neutralizingprolactin receptor antibody IgG1-005-C04 completely prevented pregnancyin mice when tested at 30 mg/kg body weight.

Example 12 Epitope Grouping

Epitope grouping experiments were performed using Biacore by monitoringsimultaneous binding of pairs of anti-PRLR antibodies to ECD-PRLR (SEQID NO: 70). Briefly, the first antibody was covalently immobilized tothe sensor chip through primary amine coupling usingn-hydroxysuccinamide (NHC) and N-ethyl-N′-dimethylaminopropylcarbodiimide (EDC). Unoccupied binding sites on the surface were thenblocked with ethanolamide. Soluble ECD-PRLR (SEQ ID NO: 70) was capturedon the surface via the immobilized antibody, therefore, the epitope ofthe capture antibody is blocked for all bound ECD-PRLR molecules. Asecond antibody was immediately passed over the surface to bind to theimmobilized ECD-PRLR. Two antibodies recognizing the same or overlappingepitopes cannot bind to the ECD-PRLR, whereas antibodies with distinctepitopes are able to bind. The antibody surface was regenerated withglycine, pH 2.8, to remove bound proteins and then the process wasrepeated with other antibodies. All combinations of antibodies weretested. Representative results are shown in Table 7. The antibodies006-H08, 002-H06, 002-H08, 006-H07 and XHA06983 competitively bound toeach other on ECD-PRLR, indicating that they target overlapping epitopes(epitope group 1, table 6). In addition, the antibodies competitivelybound to PRL, which is also the case for 001-E06 (epitope group 2, table6). This antibody targets a different site of ECD-PRLR than the aforementioned ones. Finally, the antibody 005-C04 competitively bound toHE06.642 and XHA06.642 without being competitive to PRL (epitope group3, table 6).

TABLE 7 Groups of antibodies which target overlapping epitopes on theextracellular domain (ECD) of the human prolactin receptor (PRLR)Competition to Antibody Epitope group prolactin 006-H08 1 Yes 002-H06 1Yes 002-H08 1 Yes 006-H07 1 Yes 001-E06 2 Yes 005-C04 3 No HE06.642 3 NoXHA06.642 3 No XHA06.983 1 Yes

Example 13 Cross-Reactivity of Antibodies on Mouse and Human PRLRExpressed on Cell Surfaces

In order to determine the binding characteristics of the anti-PRLRantibodies on mouse and human PRLR expressed on cells, binding wastested by flow cytometry on HEK293 cells stably expressing the human andmurine PRLR, respectively. The cells as well as the parental HEK293 cellline without PRLR were harvested, centrifuged and resuspended atapproximately 5×10⁶ cells/ml in 1×PBS containing 2% FBS and 0.1% sodiumazide (FACS buffer). The antibodies 005-C04, 001-E06 and HE06.642 werediluted to 2-fold final concentration in FACS buffer and added toappropriate sample wells (50 μl/well). For secondary antibody andautofluorescence controls, 50 μl FACS buffer was added to appropriatewells. 50 μl of cell suspension was added to each sample well. Sampleswere incubated at 4° C. for one hour, washed twice with cold FACS bufferand resuspended in FACS buffer containing PE-conjugated goat anti-humanIgG at a 1:100 dilution. Following a 30 min incubation at 4° C., cellswere washed twice with cold FACS buffer, resuspended in FACS buffercontaining 1 mg/ml propidium iodide (Invitrogen, San Diego, Calif.) andanalyzed by flow cytometry. As shown in FIG. 13, the antibodies 005-C04and 001-E06 bound to human and murine PRLR on these cells, whileHE06.642 only bound to the human PRLR. This observation is consistentwith the finding reported in example 9 about the missing efficacy ofHE06.642 in the murine PRLR-dependent luciferase reporter gene assay.Although 005-C04 and HE06.642 competitively bound to human PRLR, thedifferent binding properties of both antibodies with respect to themurine PRLR indicate differences in their epitope specificity.

Example 14 Inhibitory Activity of Fab and scFv Antibodies on CellularSignaling Cascades

To functionally characterize the activity of the Fab and scFv screeninghits on the PRLR-triggered signaling cascade, the inhibition ofphosphorylation on PRLR itself, and on the transcriptional regulatorsERK1/2 and STAT5 in human T47D cells treated with prolactin wasmeasured. T47D cells were grown in RPMI containing 2 mM L-glutamine, 10%charcoal stripped FBS and insulin-transferrin-selenium-A (Gibco). Cellswere seeded on 6 well plates or 96-well plates at a density of 1.5×10⁶cells per well. The next day, growth medium was renewed. On the third,day cells were starved for 1 hour in serumfree RPMI. Afterwards cellswere incubated with or without different doses of neutralizing PRLRantibodies or unspecific control antibody in the presence of 500 ng/mlhuman prolactin for 5 min. Afterwards cells were rinsed and lysed inlysis buffer. Lysates were centrifuged and the supernatants were frozenat −80° C. Samples were tested by ELISA according to the DuoSet IC“Human Phospho-Prolactin R” kit (R&D Systems) for measurement of PRLRphosphorylation, according to the PathScan Phospho-STAT5 (Tyr694)Sandwich ELISA kit (Cell Signaling Technology; #7113) for measurement ofSTAT5 phosphorylation and according to the Phospho-ERK1/ERK2 kit (R&DSystems) for measurement of ERK1/2 phosphorylation. Table 8 provides anoverview about the antagonistic activity of a selection of screeninghits in Fab or scFv format at a fixed dose of 7.5 μg per ml.

TABLE 8 Antagonistic activity of a selection of screening hits on thephosphorylation of PRLR, ERK1/2 and STAT5 as determined by ELISAs oncell lysates of the human breast cancer cell line T47D Inhibition ofphosphorylation in % at a fixed antibody dose (7.5 μg/ml) Antibody PRLRERK1/2 STAT5 006-H08* 100 100 100 002-H06° 92 86 72 002-H08° 100 100 98006-H07* 88 85 73 001-E06° 63 45 36 Negative control 2 9 0 *scFv format,°Fab format

Example 15 Neutralizing PRLR Antibodies Inhibit Lactation in Mice

Adult NMRI females were mated with NMRI males. On postpartal day 1,litter size was adjusted to 8 mice per lactating mother. The weight ofthe offspring was determined daily in the morning starting on postpartalday 1. Lactating mothers remained either untreated (closed circles inFIG. 14A, B) or were treated intraperitoneally with either unspecificantibody (10 mg/kg body weight; open circles in FIG. 14A,B), or withneutralizing PRLR antibody 005-C04 containing murine IgG2a constantdomains (=IgG2a 005-C04; 10 mg/kg, closed triangles in FIG. 14A, B) orwith neutralizing PRLR antibody IgG2a 005-C04 (30 mg/kg, open trianglesin FIG. 14A, B). Group size was 5-6 lactating mothers per experimentalgroup. Mothers were treated with specific or unspecific controlantibodies on postpartal day 1, 3, 6, 9, 10, and 12 (indicated witharrows in FIG. 14A, B). The results are depicted in FIG. 14. FIG. 14Ashows for each postpartal day the daily litter weight gain expressed aspercentage of the respective litter weight on day 1. From postpartal day8 onwards there is a significant difference in litter weight gainbetween offspring from mothers treated with neutralizing PRLR antibodiesand offspring from mothers that remained untreated or receivedunspecific control antibodies. Due to ethical reasons several littershad to be killed on postpartal day 10 in the experimental group ofmothers receiving the highest dose of the neutralizing PRLR antibody. InFIG. 14B the results are depicted in a different way.

The differential litter weight gain from day to day is depicted andexpressed as percentage of the litter weight on postpartal day 1.Basically FIG. 14B shows the slope of the graphs depicted in FIG. 14A.The differential daily increase in litter weight oscillates around 30%of the starting litter weight on postpartal day 1 for litters fromuntreated mothers or mothers treated with the unspecific antibody. Thereis a significant severe reduction in daily litter weight increase inlitters from mothers treated with the neutralizing PRLR antibody at 30mg/kg body weight from day 7 onwards (*p<0.05; ***p<0.005 vs. littersfrom mothers treated with unspecific antibody). From postpartal day 11onwards, daily litter weight increase is significantly diminished alsoin litters from mothers treated with the neutralizing PRLR antibody at10 mg/kg if compared to litters from mothers treated with unspecificcontrol antibodies (p<0.05 vs. litters from mothers treated withunspecific antibody). In conclusion, there are dose-dependent effects ofthe neutralizing PRLR antibody IgG2a 005-C04 on lactation inhibition.FIG. 14C shows histological sections of the mammary glands fromlactating mothers of the different experimental groups. Mammary glandsof untreated mothers and mothers treated with unspecific controlantibodies are filled with ducts producing milk. In contrast, there aresigns of mammary gland involution in mothers treated with theneutralizing PRLR antibody IgG2a 005-C04. Black arrows in FIG. 14C pointto fatty islands in the mammary gland tissue (see dose-dependent effectof the specific antibody IgG2a 005-C04 on the extent of mammary glandinvolution (FIG. 14C)). In addition, the expression of the major milkproteins beta-casein (Csn-2), whey acidic protein (WAP), and IGF-1 inthe mammary glands of mothers from the different experimental groupswere analyzed (FIG. 14D). Gene expression was normalized to theexpression of TATA-box binding protein (TBP). The neutralizing PRLRantibody IgG2a 005-C04 dose-dependently decreased milk proteinexpression whereas the unspecific antibody (10 mg/kg) was without anysignificant effect.

The neutralizing PRLR antibody IgG2a 005-C04 dose-dependently blockedlactation and lead to mammary gland involution in lactating micedemonstrating its usefullness for lactation inhibition.

Example 16 Neutralizing PRLR Antibodies are Suitable for the Treatmentof Benign Breast Disease

An activating PRLR mutation or local or systemic hyperprolactinemia canprovoke benign breast disease. Therefore, a hyperprolactinemic mousemodel to induce enhanced proliferation in the mammary gland (hallmark ofthe most severe forms of benign breast disease) was employed. On day 0,12 week old female Balb/c mice received a pituitary isograft under thekidney capsule or remained unoperated. Pituitary isografted miceremained untreated or were treated intraperitoneally with eitherunspecific antibody (10 mg/kg), neutralizing PRLR antibody 005-C04 inIgG1 format (=IgG1 005-C04; 10 mg/kg), or neutralizing PRLR antibodyIgG1 005-C04(30 mg/kg) on day 0, 3, 7, 11, and 15. Experimental groupsize was 8-10 animals. On day 17 after pituitary transplantation micewere sacrificed. Two hours before death, animals received anintraperitoneal injection of BrdU to monitor epithelial cellproliferation. The left inguinal mammary gland was fixed in Carnoy'ssolution and mammary gland whole mounts were prepared and stained withCarmine alaune (FIG. 15A). The right inguinal mammary gland was fixed in4% phosphate-buffered formaline overnight. Mammary glands weresubsequently embedded in paraffin and BrdU immunostainings wereperformed as described previously (Endocrinology 149(8):3952-3959;2009).In addition, we performed pSTAT5 immunostainings (anti pSTAT5 antibodyfrom abcam, ab32364, diluted 1:60) to monitor the inhibition ofPRLR-mediated signaling in response to treatment with neutralizing PRLRantibodies. FIG. 15A shows magnifications of mammary gland whole mountsfrom the different experimental groups. Mammary glands of adult micethat did not receive a pituitary show ducts and endbuds, whereas thereis extreme side branching and formation of alveolar structures in micereceiving a pituitary isograft. Treatment with the unspecific antibody(10 mg/kg) did not inhibit side branching and formation of alveolarstructures. In contrast, treatment with the neutralizing antibody IgG1005-C04at 10 mg/kg body weight leads to complete inhibition of sidebranching in 8 out of 10 animals receiving a pituitary isograft andtreatment with IgG1 005-C04at 30 mg/kg completely inhibits sidebranching in 9 out of 9 animals receiving a pituitary isograft.Histological analysis and BrdU immunostaining are depicted in FIG. 15B.Pituitary isografting leads to epithelial hyperplasia that is notinhibited by treatment with the unspecific antibody, whereas there is noepithelial hyperplasia in mice harbouring a pituitary isograft andtreated with the neutralizing PRLR antibody at a dose of 10 or 30 mg/kgbody weight. Some of the BrdU-positive cells, reflecting cells in theS-phase of the cell cylcle which are going to divide, are indicated bywhite arrows in FIG. 15B. Mice treated with the neutralizing antibodyIgG1 005-C04 (30 mg/kg body weight) showed almost complete inhibition ofepithelial cell proliferation in mammary glands. Some of the cellspositive for phospho-STAT5 are indicated by white arrows in FIG. 15C.Treatment with 30 mg/kg IgG1 005-C04 lead to complete inhibition ofSTAT5 phosphorylation, indicating complete blockade of PRLR-mediatedsignaling.

The results from FIG. 15A, B, and C demonstrated that neutralizing PRLRantibodies are suitable for the treatment of mastopathia, a benignproliferative disease of the mammary gland. Neutralizing PRLR antibodiesinhibit mammary epithelial cell proliferation and activation ofphospho-STAT5.

Example 17 Treatment of Benign Prostate Hyperplasia with NeutralizingPRLR Antibodies

Benign prostate hyperplasia was established in male Balb/c mice bygrafting of two pituitaries under the kidney capsule at the age of 8weeks. A control group remained unoperated. Mice receiving pituitaryisografts remained untreated or received intraperitoneal injections ofeither an unspecific antibody (10 mg/kg), or the neutralizing PRLRantibody 005-C04 containing murine IgG2a constant domains (=IgG2a005-C04) at doses of 10 and 30 mg/kg body weight. Antibody injectionswere performed starting on the day of pituitary transplantation (=day0), and on day 3, day 7, day 11, day 15, day 18, day 22, and day 25after pituitary transplantation. Mice were sacrificed on day 28. Therelative weight of the ventral prostate was determined. Results aredepicted in FIG. 16. Pituitary isografting resulted in an increase inrelative prostate weight. Treatment with 10 mg/kg and 30 mg/kgneutralizing PRLR antibody IgG2a 005-C04 reduced prostate weight whereastreatment with unspecific control antibody was without any effect.Neutralizing PRLR antibodies are therefore suitable for the treatment ofbenign prostate hyperplasia.

On day 18 after pituitary isografting it became evident that hair growthwas diminished in animals receiving pituitary isografts. NeutralizingPRLR anibodies stimulated hair growth under hyperprolactinemicconditions. Representative photographs are shown in FIG. 17. Thereforeneutralizing PRLR antibodies can be used for the treatment ofhyperprolactinemic hair loss.

Example 18 Effect of Neutralizing PRLR Antibodies on Hair Growth

The dorsal hair of 8 weeks old male and female C57BL/6 mice was removedusing electric shawers as descibed previously (British Journal ofDermatology 2008;159:300-305). Hyperprolactinemia was induced in somegroups by pituitary isografting under the kidney capsule, animals in theremaining groups were normoprolactinemic. Animals were treated withspecific PRLR antibodies (IgG2a 005-C04) or unspecific controlantibodies (30 mg/kg, intraperitoneally) once weekly (starting on day 0which is the day of pituitary isografting). Subsequent antibodyinjections were performed on days 7 and 14. After three weeks, theregrown hair was visible as dark on the pinkish-white shaved skin, andthe percentage of the shaved area that became dark was measured. Femalemice were killed 15 days after shaving and male mice were sacrificed 18days after shaving.

The following experimental groups were used (group size was 6 mice):

-   -   1. shaved females    -   2. shaved females with pituitary isograft    -   3. shaved females with pituitary isograft+30 mg/kg unspecific        antibody IgG2a 005-C04 once weekly    -   4. shaved females with pituitary isograft+30 mg/kg specific        antibody once weekly    -   5. shaved females+30 mg/kg unspecific antibody once weekly    -   6. shaved females+30 mg/kg specific antibody once weekly    -   7. shaved males    -   8. shaved males with pituitary isograft    -   9. shaved males with pituitary isograft+30 mg/kg unspecific        antibody once weekly    -   10. shaved males with pituitary isograft+30 mg/kg specific        antibody IgG2a 005-C04 once weekly    -   11. shaved males+30 mg/kg unspecific antibody once weekly    -   12. shaved males+30 mg/kg specific antibody once weekly

Representative pictures from animals of the different groups aredepicted in FIG. 18, the percentage of the area regrown with hair isindicated in FIG. 18.

Neutralising PRLR antibodies, but not unspecific antibodies, stimulatehair regrowth under hyper- and normoprolactinemic conditions in male andfemale mice. Neutralising PRLR antibodies are therefore suitable totreat hair loss in women and men under hyper- and normoprolactinemicconditions.

Example 19 Inhibition of Enhanced Mammary Epithelial Cell Proliferationby Neutralizing PRLR Antibodies

To test the effect of neutralizing PRLR antibodies on enhanced mammaryepithelial cell proliferation activated by combined hormone therapy(i.e. estrogen plus progestin therapy) a previously described mousemodel that allowed for the quantification of proliferative effects inthe uterus and the mammary gland was employed (Endocrinology149:3952-3959,2008). 6 week old C57BL/6 female mice were ovariectomized.2 weeks after ovariectomy, animals were treated subcutaneously withdaily injections of either vehicle (ethanol/arachisoil 10%/90%) or 100ng estradiol plus 100 mg/kg progesterone for two weeks. Animals weretreated once weekly with intraperitoneal injections of neutralizing PRLRantibodies (10 mg/kg and 30 mg/kg) in the murine IgGa format orunspecific antibody (30 mg/kg) for three weeks. Autopsy was performed onday 36 after ovariectomy. Two hours before death animals received anintraperitoneal injection of bromodeoxyuridine (BrdU) dissolved inphosphate buffered saline (70 mg/kg body weight). The proximal ⅔ of theright inguinal mammary gland was analyzed for mammary epithelial cellproliferation (BrdU immunostaining) as described previously(Endocrinology 149:3952-3959,2008).

The experiment comprised the following groups:

-   -   1. ovariectomized animals treated with vehicle    -   2. ovariectomized animals treated with 100 ng estradiol    -   3. ovariectomized animals treated with 100 ng estradiol (E) and        100 mg/kg progesterone (P)    -   4. ovariectomized animals treated with E+P and 10 mg/kg specific        antibody 005-C04    -   5. ovariectomized animals treated with E+P and 30 mg/kg specific        antibody 005-C04    -   6. ovariectomized animals treated with E2+P and 30 mg/kg        unspecific control antibody

The results are shown in FIG. 19. The absolute number of proliferatingductal epithelial cells within 4 cross-sections of the mammary gland wasevaluated. The medians are depicted as horizontal bars. Epithelial cellproliferation in ovariectomized, vehicle treated mice is rather low.Estradiol treatment leads to some stimulation of epithelial cellproliferation, maximal mammary epithelial cell proliferation is observedunder estrogen plus progesterone treatment (FIG. 19). Treatment withneutralising prolactin receptor antibody 005-C04 but not with unspecificcontrol antibody leads to a dose-dependent decrease in mammaryepithelial cell proliferation almost back to estradiol-only levels.

Neutralising PRLR antibodies are therefore suitable to treat enhancedmammary epithelial cell proliferation under combined hormone therapy,i.e. estradiol plus progesterone treatment.

Example 20 Treatment of Adenomyosis Uteri (=Endometriosis Interna) inSHN Mice with Neutralizing PRLR Antibodies

To test the efficacy of neutralizing PRLR antibodies in endometriosis,the adenomyosis uteri model in SHN mice relying on systemichyperprolactinemia was employed (Acta anat. 116:46-54,1983).Hyperprolactinemia in SHN mice was induced by pituitary isograftingunder the kidney capsule of 7 weeks old female mice (Acta anat.116:46-54,1983). Neutralizing PRLR antibodies (10 mg/kg or 30 mg/kg) orunspecific antibodies (30 mg/kg) were administered intraperitoneallystarting one week after pituitary isografting. The infiltration of theuterine muscular layer by glandular tissue was assessed as describedpreviously (Laboratory Animal Science 1998,48:64-68). Treatment with theantibodies was performed for 9 weeks once and twice weekly byintraperitoneal injections. At autopsy (day 70 after pituitarytransplantation), uteri were fixed overnight in buffered 4% formalin andembedded in paraffin. The degree of adenomyosis (=endometriosis interna)was assessed as follows:

-   Grade 0=no adenomyosis-   Grade 0.5=the inner layer of the myometrium looses its concentric    orientation-   Grade 1=endometrial glands invading the inner layer of the    myometrium-   Grade 2=endometrial glands between the inner and outer layer of the    uterine myometrium-   Grade 3=endometrial glands invading the outer layer of the uterine    myometrium-   Grade 4=endometrial glands outside of the outer layer of the uterine    myometrium

The experiment comprised the following experimental groups:

-   -   1. Animals without pituitary transplantation, i.e.        normoprolactinemic mice    -   2. Animals with pituitary transplantation, i.e.        hyperprolactinemic mice    -   3. Animals with pituitary transplantation, treated with        unspecific control antibody once weekly at a dose of 30 mg/kg    -   4. Animals with pituitary transplantation, treated with        unspecific control antibody twice weekly at a dose of 30 mg/kg    -   5. Animals with pituitary transplantation, treated with the        neutralizing prolactin receptor antibody 005-C04 in the murine        IgG2a format once weekly at a dose of 10 mg/kg    -   6. Animals with pituitary transplantation, treated with the        neutralizing prolactin receptor antibody 005-C04 in the murine        IgG2a format twice weekly at a dose of 10 mg/kg    -   7. Animals with pituitary transplantation, treated with the        neutralizing prolactin receptor antibody 005-C04 in the murine        IgG2a format once weekly at a dose of 30 mg/kg    -   8. Animals with pituitary transplantation, treated with the        neutralizing prolactin receptor antibody 005-C04 in the murine        IgG2a format twice weekly at a dose of 30 mg/kg

The results are depicted in FIG. 20. The scores for each animal in eachtreatment group are given individually and the medians for eachtreatment group are shown as horizontal bars. Normoprolactinemic micedevelop endometriosis interna to some degree (median diseasescore=0.25). Hyperprolactinemia due to pituitary isografting enhancesthe disease score and more animals suffer from the disease (mediandisease score=2.5). Whereas treatment with 30 mg/kg unspecific antibodyonce or twice weekly had no influence on the disease, treatment withspecific neutralizing antibodies shows a dose-dependent decrease in thedisease score. Notably, all animals receiving either 10 or 30 mg/kgspecific antibody twice weekly were completely cured and their diseasescore was significantly lower than the disease score ofnormoprolactinemic mice (FIG. 20). Neutralising PRLR antibodies aretherefore suitable to treat endometriosis interna (=adenomyosis uteri)and endometriosis externa in women.

1. A pharmaceutical composition comprising a pharmaceutically acceptableexcipient and an antibody or antigen-binding fragment thereof, wherebythe antibody competes to the antibodies 006-H08, 005-C04, 002-H06,002-H08, 006-H07, or 001-E06 for binding to the epitopes of theextracellular domain of the prolactin receptor and human polymorphicvariants thereof, and whereby the amino acid sequence of theextracellular domain of the prolactin receptor corresponds to SEQ ID NO:70, and the nucleic acid sequence corresponds to SEQ ID NO: 71, andwhereby the composition antagonizes prolactin receptor mediatedsignaling.
 2. Pharmaceutical composition according to claim 1, a.whereby the amino acid sequences of the variable heavy and light regionsare at least 60%, or more preferred 70%, or 80%, still more preferred atleast 90% and most preferred at least 95% identical to the sequences ofthe antibodies 006-H08, 005-C04, 002-H06, 002-H08, 006-H07, or 001-E06according to table 5, or b. whereby the amino acid sequences of the CDRregions are at least 60%, or more preferred 70%, or 80%, still morepreferred at least 90% and most preferred at least 95% identical to thesequences of the antibodies 006-H08, 005-C04, 002-H06, 002-H08, 006-H07,or 001-E06 according to table
 5. 3. A pharmaceutical compositionaccording to claim 2, whereby a. the variable heavy chain contains theCDR sequences corresponding to SEQ ID NO: 1, 7 and 13 and the variablelight chain contains the CDR sequences corresponding to SEQ ID NO: 18,24, and 29; or b. the variable heavy chain contains the CDR sequencescorresponding to SEQ ID NO: 2, 8 and 13 and the variable light chaincontains the CDR sequences corresponding to SEQ ID NO: 19, 25, and 30;or c. the variable heavy chain contains the CDR sequences correspondingto SEQ ID NO: 3, 9 and 14 and the variable light chain contains the CDRsequences corresponding to SEQ ID NO: 20, 24, and 31; or d. the variableheavy chain contains the CDR sequences corresponding to SEQ ID NO: 4, 10and 15 and the variable light chain contains CDR sequences correspondingto SEQ ID NO: 21, 26, and 32; or e. the variable heavy chain containsthe CDR sequences corresponding to SEQ ID NO: 5, 11 and 16 and thevariable light chain contains the CDR sequences corresponding to SEQ IDNO: 22, 27, and 30; or f. the variable heavy chain contains the CDRsequences corresponding to SEQ ID NO: 6, 12 and 17 and the variablelight chain contains the CDR sequences corresponding to SEQ ID NO: 23,28, and
 33. 4. Pharmaceutical composition according to claims 1 to 3,whereby the antibody a. 006-H08 comprises a variable heavy regioncorresponding to a nucleic acid sequence according to SEQ ID NO: 46 anamino acid sequence according to SEQ ID NO: 34; and a variable lightregion with a nucleic acid sequence according to SEQ ID NO: 52, and anamino acid sequence according to SEQ ID NO: 40, b. 002-H06 comprises anantibody having a variable heavy region corresponding to a nucleic acidsequence according to SEQ ID NO: 47, an amino acid sequence according toSEQ ID NO: 35; and a variable light region with a nucleic acid sequenceaccording to SEQ ID NO: 53, and an amino acid sequence according to SEQID NO: 41, c. 002-H08 comprises an antibody having a variable heavyregion corresponding to a nucleic acid sequence according to SEQ ID NO:48, an amino acid sequence according to SEQ ID NO: 36; and a variablelight region with a nucleic acid sequence according to SEQ ID NO: 54,and an amino acid sequence according to SEQ ID NO: 42, d. 006-H07comprises an antibody having a variable heavy region corresponding to anucleic acid sequence according to SEQ ID NO: 49, an amino acid sequenceaccording to SEQ ID NO: 37; and a variable light region with a nucleicacid sequence according to SEQ ID NO: 55, and an amino acid sequenceaccording to SEQ ID NO: 43, e. 001-E06 comprises an antibody having avariable heavy region corresponding to a nucleic acid sequence accordingto SEQ ID NO: 50 an amino acid sequence according to SEQ ID NO: 38; anda variable light region with a nucleic acid sequence according to SEQ IDNO: 56, and an amino acid sequence according to SEQ ID NO: 44, and f.005-C04 comprises an antibody having a variable heavy regioncorresponding to a nucleic acid sequence according to SEQ ID NO: 51 anamino acid sequence according to SEQ ID NO: 39; and a variable lightregion with a nucleic acid sequence according to SEQ ID NO: 57, and anamino acid sequence according to SEQ ID NO:
 45. 5-8. (canceled)
 9. Apharmaceutical composition according to claim 1 further comprising atleast one other agent. 10-25. (canceled)
 26. A pharmaceuticalcomposition according to claim 1, further comprising an estrogen.
 27. Apharmaceutical composition according to claim 2 further comprising atleast one other agent.
 28. A pharmaceutical composition according toclaim 2 further comprising an estrogen.
 29. A method for treating orpreventing endometriosis, adenomyosis (endometriosis interna), hotflashes, benign breast disease, mastalgia, benign prostate hyperplasia,hyper- and normoprolactinemic hair loss comprising the step ofadministering to a patient in need thereof an antibody according toclaim
 1. 30. A method of contraception or for preventing pregnancycomprising the step of administering to a patient in need thereof anantibody according to claim
 1. 31. A method for inhibition of lactationcomprising the step of administering to a patient in need thereof anantibody according to claim
 1. 32. A method for treating or preventingendometriosis, adenomyosis (endometriosis interna), hot flashes, benignbreast disease, mastalgia, benign prostate hyperplasia, hyper- andnormoprolactinemic hair loss comprising the step of administering to apatient in need thereof an antibody according to claim
 2. 33. A methodof contraception or for preventing pregnancy comprising the step ofadministering to a patient in need thereof an antibody according toclaim
 2. 34. A method for inhibition of lactation comprising the step ofadministering to a patient in need thereof an antibody according toclaim 2.